CN110187235B - Distributed power line fault positioning system and method based on traveling wave speed dynamic measurement - Google Patents
Distributed power line fault positioning system and method based on traveling wave speed dynamic measurement Download PDFInfo
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- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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Abstract
The invention discloses a distributed power line fault positioning system and a distributed power line fault positioning method based on traveling wave velocity dynamic measurement. The distance measuring devices which independently operate can know the operating states and the measuring results of other related devices, can verify the measuring results of the device, improves the positioning accuracy of the device, and can quickly find out fault/abnormal nodes through mutual verification. And because of adopting the distributed system architecture of the hand in hand, can filter and reject the bad data that influences the precision greatly, have further improved the measuring precision and accuracy of the system again. The actual wave speed of the traveling wave generated by the fault is measured in real time by using the same type of power wires or power cables in the area adjacent to the fault point, so that the accuracy of positioning and ranging is further improved.
Description
Technical Field
The invention relates to a fault positioning method of a power line, in particular to a distributed power line fault positioning system and method based on traveling wave speed dynamic measurement.
Background
The 10kV automatic blocking and power through line (Automatic blocking and Continuous transmission line) and the cable refer to an important transmission line connected between two adjacent substations and distribution stations along the railway, and the heavy duty of power supply of shoulder-negative line stations, interval loads and signal equipment. The power supply system and the railway substation and the distribution substation form a power supply system special for the railway. The complex and changeable environment of the railway self-closing through line body is easy to generate various faults, wherein permanent faults which are difficult to check have the greatest threat to the operation safety of the railway. As an indispensable part of a railway power supply system, there is a very high demand for reliability of power supply. Once the self-closing through line fails, the running safety of the train is seriously threatened, and even immeasurable losses are brought to the life safety of the national property and people. For the self-closing through line with extremely high power supply reliability, an effective fault quick positioning method is needed to be found out, faults are removed timely and accurately, and railway power supply is restored.
Aiming at the positioning of the power line faults, the current situation of research at home and abroad is as follows:
(1) Impedance method
Impedance methods are one method of fault localization in electrical power systems. When a fault occurs, the distance from the fault point to the line measurement end is calculated by analyzing the voltage and current amounts measured by the measurement end of the line. The principle of the method is that the reactance or impedance of the section of line is calculated by the measured voltage and current, and the reactance or impedance is proportional to the length of the line, so that fault location is realized. The method has simple principle, less investment, easy realization in engineering practice and no limitation of communication technology, thus receiving great attention. However, the method is also affected by excessive impedance, has the defects of poor accuracy, large error and weak adaptability, and more importantly, the method has the precondition that the line is required to be a single uniform line, so that the method cannot eliminate the influence of discontinuous wave velocity caused by large wave impedance difference in the line, and therefore, the error is larger when the method is used for positioning the fault of the self-closing through line.
(2) Off-line ranging method
The cable ranging currently uses an off-line ranging method, wherein the off-line ranging method is to unlock the terminal of a cable connector under the condition of power failure of a circuit, inject high-voltage pulse into the cable and realize ranging according to the reflected pulse of a fault point. The biggest problems of the off-line ranging method are: often, some cable sintering faults are difficult to reproduce under the impact of high-voltage pulses, so that fault ranging of the injected high-voltage pulses fails under the off-line condition. In addition, the high-voltage pulse is injected for many times, so that the insulation defective part of the cable is damaged, and the operation reliability and the service life of the whole cable are affected.
(3) S injection method
The S injection method is to inject a signal into a line by shorting the primary side when a ground short occurs in a certain phase of the line. At this time, the voltage transformer PT of the fault phase transmits a current signal to the ground point, the signal flows into the ground from the ground point, and then by tracking the signal, it can be determined which phase the fault occurs in and find out the fault point, so as to realize the positioning of the fault point. The disadvantages of this method are: the intensity of a current signal flowing into the ground is related to the power of the voltage transformer PT, and the smaller the power is, the weaker the signal is, so that tracking is difficult; when the excess resistance is large, the current flowing into the ground is shunted due to the action of the distributed capacitance, so that the intensity of a current signal is further weakened; if an arc is generated at the grounding point, the current signal flowing into the ground is not continuous, so that the trace of the current signal is difficult to track, and the method is disabled. Therefore, this method is not a good method for fault localization of the self-closing through line either.
(4) Fault section finding method
The fault section searching method mainly utilizes an automatic feeder terminal FTU, wherein the feeder terminal FTU has measuring and communication functions, can detect electric quantity in each sectional switch and each outgoing switch, then remotely reports the detected data to a control center, and the control center analyzes and processes the data, so that fault types and fault intervals are determined, and fault positioning is completed. The method has the defects that only a fault interval can be judged, the error is larger, and the accuracy cannot meet the actual requirement.
(5) Travelling wave method
The principle of the traveling wave positioning method is as follows: when the line fails, the fault voltage or current traveling wave is captured at the line measuring end, and the fault distance is obtained by analyzing the wave speed and time information, so that the fault location is completed. The traveling wave positioning method has the advantages that: the independence is strong, and the interference of external factors such as line parameters, structures and the like is avoided; the positioning time is short, the traveling wave speed is close to the light speed, and the calculation of the fault distance can be completed in a short time; the measuring precision is high, and the fault point position is directly determined instead of determining the fault interval; low cost, no need of extra large-scale equipment, and convenient arrangement and use in various places of the circuit. According to the positioning principle and the extraction mode of the traveling wave signals, the traveling wave positioning method currently comprises a single-end electric quantity positioning method and a double-end electric quantity positioning method.
① Single end electric quantity positioning method
When the line breaks down, at one end of the line, called a measuring end, the initial traveling wave and the reflected wave of the fault are captured, and the distance from the fault point to the measuring point is obtained by calculating the time difference between the traveling wave head and the measuring point.
② Double-end electric quantity positioning method
When the line fails, the two ends of the line are measuring ends, the fault initial traveling wave components are respectively received, and the fault point distance is obtained by calculating the difference between the time of the two traveling wave components reaching the measuring ends. The method has the advantages that: only the fault initial traveling wave need be considered, and the reflected and refracted waves need not be considered. Therefore, the method is easier to implement and the measurement result is more reliable.
Compared with the single-ended traveling wave positioning method, the double-ended traveling wave method needs GNSS timing and two-end communication, but can reliably position any line structure. The double-end traveling wave method only needs to detect the arrival time of the fault initial traveling wave head, so that the problems of positioning failure and the like caused by incapacitation of measurement or absence of reflected waves due to attenuation of the reflected waves by the single-end traveling wave method can be avoided. Therefore, a double-ended traveling wave method is generally adopted to realize reliable positioning. However, the range error is generally proportional to the line length, and shortening the fault section necessarily reduces the line length error. From the principle of double-ended traveling wave positioning calculation, the larger the line length error is, the lower the positioning accuracy is. And if the fault distance measurement section can be shortened, the attenuation and distortion degree of the traveling wave signal can be reduced, which is also beneficial to accurate detection of the arrival time of the fault traveling wave head. Therefore, shortening the failure section can improve positioning accuracy to some extent.
For the identification of the traveling wave head, the accurate detection of the arrival time of the fault initial traveling wave is one of key factors for realizing the accurate positioning of the fault point. The wavelet transformation is applied to detection of fault traveling wave arrival time in the later 90 s of the 20 th century, and a certain application effect is obtained. Wavelet transformation represents a great advantage over previous traveling wave head detection methods such as phase angle difference, correlation, derivative, matched filter and maximum likelihood estimation. Although wavelet transformation achieves a certain effect in the detection of the arrival time of a traveling wave head, the method has no self-adaption and needs to select proper basis functions and decomposition scales by combining signal characteristics.
Propagation speed v=c/n of electromagnetic waves in different media, wherein c is the speed of light and n is the refractive index of the media; thus: a) The propagation speed of electromagnetic waves in different media is different; b) The traveling wave generated by the fault has similar propagation behavior in the power line as the electromagnetic wave propagates in the waveguide, and the propagation speed of the traveling wave can be influenced by various factors such as the model, the diameter, the shape and the coating layer of the power line; c) The power line is erected in the field, the temperature change is large during operation, the length of the wire can change due to expansion with heat and contraction with cold, and the change can be attributed to the change of travelling wave speed in the measuring and calculating process; d) The traveling wave spectrum generated by different faults may be different, chromatic dispersion may be generated in the propagation process, and the measurement of the wave velocity may be affected. Therefore, accurate measurement of the traveling wave velocity in the ranging process plays a vital role in improving the accuracy of ranging and positioning.
In the conventional travelling wave positioning and ranging system, the wave speed is usually taken as the light speed directly, or a set empirical value is adopted, which may generate a large positioning error in practical application. The system also adopts the double-end traveling wave ranging system to measure the traveling wave velocity when the fault outside the line area is adopted, and because the parameters of the power transmission line change along with the frequency, even if the same line changes at different moments, the wave velocity values are different. Therefore, although the wave velocities are measured on the same line, the measured wave velocities at different times may have a certain error due to the influence of external environmental factors. When the traveling wave method is adopted to locate the line fault, the influence of the wave speed is eliminated by utilizing the time of the fault initial traveling wave and the fault point reflected wave reaching the bus, and the influence of the wave speed is eliminated by utilizing the time of the fault initial traveling wave, the fault point reflected wave and the opposite bus reflected wave reaching the bus by some devices. Because the method uses fault point reflected waves or opposite bus reflected waves, when the reflected waves are attenuated to be unable to be measured or no reflected waves exist, the positioning reliability and positioning precision of the method are difficult to be ensured. There is also a literature that the traveling wave velocity of a fault is measured from an adjacent line, but when the parameters of the conductors of the fault line and the adjacent line are different, the traveling wave velocities on the two lines are different. Thus, this method also produces uncontrolled positioning errors.
From the existing fault traveling wave velocity measurement method, the traditional method is poor in accuracy or limited in use condition. Therefore, the problem of how to improve the accuracy of the fault traveling wave velocity measurement is to be solved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a distributed power line fault positioning system and method based on traveling wave speed dynamic measurement, which support multi-terminal hand-in-hand redundant ranging, so as to rapidly and accurately realize fault positioning and improve the power supply reliability of a power line.
The aim of the invention is realized by the following technical scheme:
A distributed power line fault positioning method based on traveling wave speed dynamic measurement comprises the following steps:
s1: a plurality of fault traveling wave distance measuring devices are distributed on a power line and are respectively arranged at a point M k-n、……、Mk-2、Mk-1、Mk、Mk+1、Mk+2、……、Mk+N in the power line;
S2: the ground fault or the short circuit fault occurs at the point d, and the traveling wave generated by the fault sequentially propagates to the point M k、Mk-1、Mk-2、……、Mk-n leftwards and sequentially propagates to the point M k+1、Mk+2、……、Mk+N rightwards;
S3: the fault traveling wave distance measuring devices of each point respectively detect the moment when the fault traveling wave reaches the point, and the moment is recorded as T k-n、……、Tk-2、Tk-1、Tk、Tk+1、Tk+2、……、Tk+N;
S4: the fault traveling wave distance measuring device of the M k+1 point calculates real-time traveling wave velocity V=L K+2/(Tk+2-Tk+1 according to the fault traveling wave arrival time data of the adjacent M k、Mk+2 node, wherein L K+2 is the length of a power line from the M k+1 point to the M k+2 point;
s5: and calculating the distance between the fault point d and the M k point according to the real-time traveling wave speed V, and the distance L d＝(Lk+1-V*(Tk+1-Tk) and 2 between the fault point d and the M k point, wherein L k+1 is the length of a power line between the M k point and the M k+1 point.
In the process of detecting the arrival time of the fault traveling wave, the detection of a fault traveling wave head is realized by utilizing wavelet transformation, after wavelet transformation is carried out on the mode components of the traveling wave, the arrival time of the fault initial traveling wave is determined according to the position of the first mode maximum value of the wavelet coefficient of a certain scale obtained by decomposition, and the basis function and the decomposition scale of a wavelet transformation algorithm are selected by combining the type of a power line and the characteristics of the wave head.
The distributed power line fault positioning method based on the traveling wave speed dynamic measurement further comprises a line type self-learning step, wherein first, the line type self-learning step is performed by presetting the line type composition data and the wave speeds of various cables to form first generation line composition data, and a simulated fault traveling wave is actively generated for a system at a known position in the line, and each fault traveling wave distance measuring device calculates the cable type composition between the node and the simulated fault traveling wave starting position according to the time when the simulated fault traveling wave is received by the fault traveling wave distance measuring device and the simulated fault traveling wave starting position to form second generation line composition data; after each line fault occurs, each fault traveling wave distance measuring device calculates the cable type composition between the fault traveling wave distance measuring device and the current fault traveling wave starting position according to the time of receiving the fault traveling wave and the fault traveling wave starting position, and continuously iterates data to complete line type self-learning.
The distributed power line fault positioning system based on the traveling wave speed dynamic measurement comprises a plurality of fault traveling wave distance measuring devices which are distributed on a power line, wherein each fault traveling wave distance measuring device comprises a traveling wave head induction component, a low-pass filter, a high-frequency sampling chip, a high-precision time base module, a microcontroller and a hand-hold communication interface, the signal output end of the traveling wave head induction component is connected with the sampling signal input end of the high-frequency sampling chip through the low-pass filter, the clock signal output end of the high-precision time base module is connected with the clock signal input end of the high-frequency sampling chip, the signal output end of the high-frequency sampling chip is connected with the microcontroller, the microcontroller is also connected with the hand-hold communication interface through an associated data processing interface, and the adjacent fault traveling wave distance measuring devices are mutually connected through the hand-hold communication interface and a protocol;
the microcontroller is provided with a wave recording traveling wave data storage unit, a fault traveling wave rapid detection unit, a traveling wave speed dynamic measurement unit and a fault traveling wave positioning unit, wherein the wave recording traveling wave data storage unit is used for recording and storing electrical quantity change data of a pre-fault process and a post-fault process; the fault traveling wave rapid detection unit is used for detecting a fault traveling wave head; the traveling wave speed dynamic measurement unit measures the actual wave speed of the traveling wave generated by the fault in real time by using the same type of power lines in the area adjacent to the fault point; the fault traveling wave positioning unit is used for calculating the specific position of the fault point according to the recorded traveling wave data, the fault traveling wave detection data and the traveling wave speed data.
The traveling wave head induction component is a current transformer.
The traveling wave head induction component is a voltage sensor arranged on the low-voltage side of the transformer.
The distributed power line fault positioning system based on the travelling wave velocity dynamic measurement further comprises a remote data communication interface, wherein the remote data communication interface is connected with the microcontroller.
The low-pass filter is a second-order low-pass filter.
The high-precision time base module is a time base module with GNSS auxiliary time synchronization and is composed of a system clock and a GNSS clock.
The microcontroller also comprises a line type self-learning module, wherein the line type self-learning module firstly presets the formation data of the line type and the wave speed of various cables to form first generation line formation data, and actively generates a simulated fault traveling wave for the system at a known position in the line, and each fault traveling wave ranging device calculates the formation of the cable type between the node and the simulated fault traveling wave starting position according to the time of receiving the simulated fault traveling wave and the simulated fault traveling wave starting position to form second generation line formation data; after each line fault occurs, each fault traveling wave distance measuring device calculates the cable type composition between the fault traveling wave distance measuring device and the current fault traveling wave starting position according to the time of receiving the fault traveling wave and the fault traveling wave starting position, and continuously iterates data to complete line type self-learning.
The beneficial effects of the invention are as follows:
1) The invention adopts a fault positioning scheme based on multi-terminal redundant ranging, has strong independence and is not interfered by external factors such as line parameters, structures and the like; based on the traveling wave detection theory, the positioning speed is high, and the calculation of the fault distance can be completed in a short time; meanwhile, as the distributed system design is adopted, the electric quantity measuring points are arranged along the self-closing through line at a certain distance, the fault section is shortened, and the attenuation and distortion degree of the traveling wave signal are reduced.
By adopting a hand-in-hand distributed system architecture, each independently operated ranging device can complete functions in the distributed system under the condition that the system has no central master station, and the multi-terminal redundancy design ensures that the system can still normally realize fault positioning when individual measuring points cannot normally work, thereby improving the reliability of the system. The distance measuring devices are communicated through the hand communication interface and the protocol, so that each independently operated device can know the operation state and the measurement result of other related devices, the measurement result of the device can be verified by the measurement result of other related devices, the positioning accuracy of the device is improved, and the fault/abnormal node can be quickly found out through mutual verification. And because of adopting the distributed system architecture of hand in hand, in the field operation process, can filter and reject the bad data that the instantaneous external interference produces and has great influence on precision, have further improved the measuring accuracy and accuracy of the system again.
2) According to the invention, the arrival time of the fault traveling wave is respectively measured at different positions of the line by adopting the plurality of fault traveling wave distance measuring devices, and the actual wave speed of the traveling wave generated by the fault is measured in real time by utilizing the same type of power wires or power cables in the area adjacent to the fault point, so that the accuracy of positioning and distance measuring is further improved.
3) The invention realizes the detection of the fault traveling wave head by utilizing wavelet transformation, selects proper wavelet basis functions and decomposition scales by combining the type of the power line and the characteristics of the wave head, and further improves the detection precision of the moment of reaching the fault traveling wave.
4) According to the invention, by means of a plurality of electric quantity measuring points provided by the electric transmission line on-line monitoring system, under the condition of CT, fault traveling waves are captured directly by utilizing CT, under the condition of no CT (transformer), the voltage on the low-voltage side of the transformer is detected by using the voltage sensor (PT) to capture the fault traveling waves, the high-speed sampling of the fault traveling waves can be realized without modifying primary equipment, and the equipment investment is less.
5) The self-closing through line usually passes through the places without people, and the places possibly have no network or even wireless signals, so that the safety problem and the uncertainty of time delay when a public network is adopted can be avoided through the self-organizing wireless communication network, and the reliability of system communication is improved.
6) The invention adopts the time base module with GNSS auxiliary time synchronization, the module can receive the Beidou time synchronization signal, uses GPS and the like as auxiliary time synchronization, and applies the GNSS system to synchronize clocks of all devices, so that the clocks of all devices are consistent when calculating the speed, the accuracy of multi-terminal system time is ensured, and the ranging accuracy is ensured. Meanwhile, the devices are connected through the wireless network hand-in-hand to calibrate the clock together, bad data are filtered, and the positioning accuracy and stability of the system are further improved.
7) The invention has the function of self-learning the line type, and the constitution condition of the line cable is preset as a theoretical parameter, after each line fault occurs, each fault traveling wave distance measuring device calculates the constitution of the cable type between the fault traveling wave distance measuring device and the starting position of the current fault traveling wave according to the time of the fault traveling wave received by the fault traveling wave distance measuring device and the starting position of the current fault traveling wave, and the parameters of the cable type are continuously iterated and corrected, so that the self-learning function of the line type is completed, the judgment of the constitution of the line cable in the system is more attached to the actual working condition parameters, and the accuracy and the reliability of the system for judging the actual wave speed of the traveling wave are further improved. In addition, each node can obtain the data of the whole system line type through self-learning, and the mutual verification among the distributed nodes can further improve the reliability of the data of the system line type.
8) The invention adopts DMA direct memory access technology, allows hardware devices with different speeds to communicate without relying on a great deal of interrupt load of the CPU (otherwise, the CPU needs to copy the data of each segment from a source to a temporary storage and then write them back to a new place again, and in the time, the CPU cannot be used for other work); therefore, the data sampling can be synchronously carried out in the fault location calculation process, the problem of the continuous sampling time interval of the device is solved, and the system reliability is further improved.
Drawings
FIG. 1 is a schematic diagram of the arrangement position of the fault traveling wave distance measuring device in the power line;
FIG. 2 is a circuit block diagram of the fault traveling wave distance measuring device of the present invention;
fig. 3 is a schematic circuit diagram of the low-pass filter of the present invention.
Detailed Description
The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without any inventive effort, are intended to be within the scope of the present invention, based on the embodiments of the present invention.
A distributed power line fault positioning method based on traveling wave speed dynamic measurement comprises the following steps:
s1: as shown in fig. 1, a plurality of fault traveling wave distance measuring devices are distributed on a power line and are respectively installed at a point M k-n、……、Mk-2、Mk-1、Mk、Mk+1、Mk+2、……、Mk+N in the power line;
S2: the ground fault or the short circuit fault occurs at the point d, and the traveling wave generated by the fault sequentially propagates to the point M k、Mk-1、Mk-2、……、Mk-n leftwards and sequentially propagates to the point M k+1、Mk+2、……、Mk+N rightwards;
S3: the fault traveling wave distance measuring devices of each point respectively detect the moment when the fault traveling wave reaches the point, and the moment is recorded as T k-n、……、Tk-2、Tk-1、Tk、Tk+1、Tk+2、……、Tk+N;
S4: the fault traveling wave distance measuring device of the M k+1 point calculates real-time traveling wave velocity V=L K+2/(Tk+2-Tk+1 according to the fault traveling wave arrival time data of the adjacent M k、Mk+2 node, wherein L K+2 is the length of a power line from the M k+1 point to the M k+2 point;
s5: and calculating the distance between the fault point d and the M k point according to the real-time traveling wave speed V, and the distance L d＝(Lk+1-V*(Tk+1-Tk) and 2 between the fault point d and the M k point, wherein L k+1 is the length of a power line between the M k point and the M k+1 point.
According to the invention, the arrival time of the fault traveling wave is respectively measured at different positions of the line by adopting the plurality of fault traveling wave distance measuring devices, and the actual wave speed of the traveling wave generated by the fault is measured in real time by utilizing the same type of power wires or power cables in the area adjacent to the fault point, so that the accuracy of positioning and distance measuring is further improved.
In the process of detecting the arrival time of the fault traveling wave, the detection of a fault traveling wave head is realized by utilizing wavelet transformation, after wavelet transformation is carried out on the mode components of the traveling wave, the arrival time of the fault initial traveling wave is determined according to the position of the first mode maximum value of the wavelet coefficient of a certain scale obtained by decomposition, and the basis function and the decomposition scale of a wavelet transformation algorithm are selected by combining the type of a power line and the characteristics of the wave head. The detection of the fault traveling wave head is realized by utilizing wavelet transformation, and proper wavelet basis functions and decomposition scales are selected by combining the type of the power line and the characteristics of the wave head, so that the detection precision of the moment of reaching the fault traveling wave is further improved.
The distributed power line fault positioning method based on the dynamic measurement of the traveling wave speed further comprises a line type self-learning step, wherein first, the construction data of the line type (for example, the total length of the line is 200 km, the cable in the line is preset to be 50 km, the overhead line is 150 km) and the wave speeds of various cables (the wave speeds of the traveling wave on the cable and the overhead line are different) are preset, so as to form first generation line construction data, a simulated fault traveling wave is actively generated for a system at a known position in the line, and each fault traveling wave distance measuring device calculates the construction of the cable type between the node and the simulated fault traveling wave starting position according to the time when the simulated fault traveling wave is received by the fault traveling distance measuring device and the simulated fault traveling wave starting position, so as to form second generation line construction data; after each line fault occurs, each fault traveling wave distance measuring device calculates the cable type composition between the fault traveling wave distance measuring device and the current fault traveling wave starting position according to the time of receiving the fault traveling wave and the fault traveling wave starting position, and continuously iterates data to complete line type self-learning.
The invention has the function of self-learning the line type, and the constitution condition of the line cable is preset as a theoretical parameter, after each line fault occurs, each fault traveling wave distance measuring device calculates the constitution of the cable type between the fault traveling wave distance measuring device and the starting position of the current fault traveling wave according to the time of the fault traveling wave received by the fault traveling wave distance measuring device and the starting position of the current fault traveling wave, and the parameters of the cable type are continuously iterated and corrected, so that the self-learning function of the line type is completed, the judgment of the constitution of the line cable in the system is more attached to the actual working condition parameters, and the accuracy and the reliability of the system for judging the actual wave speed of the traveling wave are further improved. In addition, each node can obtain the data of the whole system line type through self-learning, and the mutual verification among the distributed nodes can further improve the reliability of the data of the system line type.
Correspondingly, based on the distributed power line fault positioning system of the dynamic measurement of the traveling wave speed, adjacent fault traveling wave distance measuring devices are in communication connection with each other through a hand-in-hand communication interface and a protocol, each fault traveling wave distance measuring device can know related information (including terminal numbers, positions, arrival time of detected fault traveling wave heads and the like) of adjacent terminals, and each fault traveling wave distance measuring device can calculate and obtain fault point positions according to own data and data of the adjacent terminals.
Specifically, in this embodiment, as shown in fig. 2, the distributed power line fault location system based on dynamic measurement of the traveling wave speed includes a plurality of fault traveling wave ranging devices distributed on a power line, where the fault traveling wave ranging devices include a traveling wave head sensing component, a low pass filter, a high frequency sampling chip, a high precision time base module, a microcontroller and a hand-hold communication interface, where a signal output end of the traveling wave head sensing component is connected with a sampling signal input end of the high frequency sampling chip through the low pass filter, a clock signal output end of the high precision time base module is connected with a clock signal input end of the high frequency sampling chip, a signal output end of the high frequency sampling chip is connected with the microcontroller, the microcontroller is further connected with the hand-hold communication interface through a related data processing interface, and adjacent fault traveling wave ranging devices are connected with each other through the hand-hold communication interface and a protocol.
In this embodiment, the traveling wave head sensing component is a current transformer (HLSR-P/SP 33 series current transformer is adopted in this embodiment, but the protection scope is not limited thereto) or a voltage sensor mounted on the low-voltage side of the transformer, specifically, under the condition of CT, the fault traveling wave is directly captured by CT, and under the condition of no CT (such as a transformer), the voltage (3.3V) on the low-voltage side of the transformer is detected by using the low-voltage sensor (PT) to capture the fault traveling wave, and the high-speed sampling of the fault traveling wave can be realized without modifying a primary device.
In this embodiment, as shown in fig. 3, the low-pass filter is a second-order Sallen-Key low-pass filter, and the protection scope is not limited thereto.
The microcontroller is provided with a wave recording traveling wave data storage unit, a fault traveling wave rapid detection unit, a traveling wave speed dynamic measurement unit and a fault traveling wave positioning unit, wherein the wave recording traveling wave data storage unit is used for recording and storing electrical quantity change data of a pre-fault process and a post-fault process; the fault traveling wave rapid detection unit is used for detecting a fault traveling wave head; the traveling wave speed dynamic measurement unit measures the actual wave speed of the traveling wave generated by the fault in real time by using the same type of power lines in the area adjacent to the fault point; the fault traveling wave positioning unit is used for calculating the specific position of the fault point according to the recorded traveling wave data, the fault traveling wave detection data and the traveling wave speed data.
Further, the microcontroller also comprises a line type self-learning module, the line type self-learning module firstly presets the composition data of the line type and the wave speed of various cables in the line to form first generation line composition data, and actively generates a simulated fault traveling wave for the system at a known position in the line, and each fault traveling wave ranging device calculates the composition of the cable type between the node and the simulated fault traveling wave starting position according to the time when the simulated fault traveling wave is received by the fault traveling wave ranging device and the simulated fault traveling wave starting position to form second generation line composition data; after each line fault occurs, each fault traveling wave distance measuring device calculates the cable type composition between the fault traveling wave distance measuring device and the current fault traveling wave starting position according to the time of receiving the fault traveling wave and the fault traveling wave starting position, and continuously iterates data to complete line type self-learning.
Preferably, the high-precision time base module is a time base module with GNSS auxiliary time synchronization, and is composed of a system clock and a GNSS clock. The time base module with GNSS auxiliary time synchronization is adopted, the module can receive Beidou time synchronization signals, GPS and the like are used as auxiliary time synchronization, a GNSS system is used for synchronizing clocks of all devices, the clocks of all devices are consistent when the speed is calculated, the accuracy of multi-terminal system time is guaranteed, and therefore ranging accuracy is guaranteed. Meanwhile, the devices are connected through the wireless network hand-in-hand to calibrate the clock together, bad data are filtered, and the positioning accuracy and stability of the system are further improved.
The distributed power line fault positioning system further comprises a remote data communication interface, wherein the remote data communication interface is connected with the microcontroller and is used for realizing data transmission of each fault traveling wave distance measuring device.
In the embodiment, the fault traveling wave distance measuring devices in the system realize communication through the wireless network hand-held communication interface and the protocol, and the safety problem and the uncertainty of time delay when a public network is adopted can be avoided through the self-organizing wireless communication network, so that the reliability of the system communication is improved.
In addition, the present invention employs DMA direct memory access technology, allowing hardware devices of different speeds to communicate without relying on the significant interrupt load of the CPU (otherwise, the CPU would have to copy each piece of data from the source to a register and then write them back again to a new place, at which time the CPU would be unusable for other tasks); therefore, the data sampling can be synchronously carried out in the fault location calculation process, the problem of the continuous sampling time interval of the device is solved, and the system reliability is further improved.
The foregoing is merely a preferred embodiment of the invention, and it is to be understood that the invention is not limited to the form disclosed herein but is not to be construed as excluding other embodiments, but is capable of numerous other combinations, modifications and environments and is capable of modifications within the scope of the inventive concept, either as taught or as a matter of routine skill or knowledge in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the invention are intended to be within the scope of the appended claims.
Claims (7)
1. The distributed power line fault positioning method based on the traveling wave speed dynamic measurement is characterized by comprising the following steps of:
s1: a plurality of fault traveling wave distance measuring devices are distributed on a power line and are respectively arranged at a point M k-n、……、Mk-2、Mk-1、Mk、Mk+1、Mk+2、……、Mk+N in the power line;
S2: the ground fault or the short circuit fault occurs at the point d, and the traveling wave generated by the fault sequentially propagates to the point M k、Mk-1、Mk-2、……、Mk-n leftwards and sequentially propagates to the point M k+1、Mk+2、……、Mk+N rightwards;
S3: the fault traveling wave distance measuring devices of each point respectively detect the moment when the fault traveling wave reaches the point, and the moment is recorded as T k-n、……、Tk-2、Tk-1、Tk、Tk+1、Tk+2、……、Tk+N;
S4: the fault traveling wave distance measuring device of the M k+1 point calculates real-time traveling wave velocity V=L K+2/（Tk+2-Tk+1 according to the fault traveling wave arrival time data of the adjacent M k、Mk+2 node, wherein L K+2 is the length of a power line from the M k+1 point to the M k+2 point;
S5: calculating the distance between a fault point d and a M k point according to the real-time traveling wave speed V, and the distance L d=（Lk+1-V*（Tk+1-Tk) and 2 between the fault point d and a M k point, wherein L k+1 is the length of a power line between the M k point and the M k+1 point;
The method comprises the steps of a line type self-learning step, namely presetting the composition data of the line type and the wave speed of various cables in the line to form first generation line composition data, actively generating a simulated fault traveling wave for a system at a known position in the line, and calculating the composition of the cable type between the simulated fault traveling wave and a simulated fault traveling wave starting position by each fault traveling wave ranging device according to the time of receiving the simulated fault traveling wave and the simulated fault traveling wave starting position of each fault traveling wave ranging device to form second generation line composition data; after each line fault occurs, each fault traveling wave ranging device calculates the composition of the cable type between the fault traveling wave ranging device and the starting position of the current fault traveling wave according to the time of receiving the fault traveling wave and the starting position of the fault traveling wave, continuously iterates data, and completes self-learning of the line type;
In the process of detecting the arrival time of the fault traveling wave, the detection of a fault traveling wave head is realized by utilizing wavelet transformation, after wavelet transformation is carried out on the mode components of the traveling wave, the arrival time of the fault initial traveling wave is determined according to the position of the first mode maximum value of the wavelet coefficient of a certain scale obtained by decomposition, and the basis function and the decomposition scale of a wavelet transformation algorithm are selected by combining the type of a power line and the characteristics of the wave head.
2. Distributed power line fault positioning system based on travelling wave velocity dynamic measurement, its characterized in that: the distributed power line fault location method based on the travelling wave speed dynamic measurement comprises a plurality of fault travelling wave distance measuring devices which are distributed on a power line, wherein each fault travelling wave distance measuring device comprises a travelling wave head induction component, a low-pass filter, a high-frequency sampling chip, a high-precision time base module, a microcontroller and a hand-hold communication interface, the signal output end of the travelling wave head induction component is connected with the sampling signal input end of the high-frequency sampling chip through the low-pass filter, the clock signal output end of the high-precision time base module is connected with the clock signal input end of the high-frequency sampling chip, the signal output end of the high-frequency sampling chip is connected with the microcontroller, the microcontroller is also connected with the hand-hold communication interface through a related data processing interface, and the adjacent fault travelling wave distance measuring devices are mutually connected through the hand-hold communication interface and a protocol;
The microcontroller is provided with a wave recording traveling wave data storage unit, a fault traveling wave rapid detection unit, a traveling wave speed dynamic measurement unit and a fault traveling wave positioning unit, wherein the wave recording traveling wave data storage unit is used for recording and storing electrical quantity change data of a pre-fault process and a post-fault process; the fault traveling wave rapid detection unit is used for detecting a fault traveling wave head; the traveling wave speed dynamic measurement unit measures the actual wave speed of the traveling wave generated by the fault in real time by using the same type of power lines in the area adjacent to the fault point; the fault traveling wave positioning unit is used for calculating the specific position of a fault point according to the recorded traveling wave data, the fault traveling wave detection data and the traveling wave speed data;
The microcontroller also comprises a line type self-learning module, wherein the line type self-learning module firstly presets the composition data of the line type and the wave speed of various cables to form first generation line composition data, and actively generates a simulated fault traveling wave for the system at a known position in the line, and each fault traveling wave ranging device calculates the composition of the cable type between the simulated fault traveling wave and the simulated fault traveling wave starting position according to the time when the simulated fault traveling wave is received by the fault traveling wave ranging device and the simulated fault traveling wave starting position to form second generation line composition data; after each line fault occurs, each fault traveling wave distance measuring device calculates the cable type composition between the fault traveling wave distance measuring device and the current fault traveling wave starting position according to the time of receiving the fault traveling wave and the fault traveling wave starting position, and continuously iterates data to complete line type self-learning.
3. The distributed power line fault location system based on dynamic measurement of traveling wave velocity according to claim 2, wherein: the traveling wave head induction component is a current transformer.
4. The distributed power line fault location system based on dynamic measurement of traveling wave velocity according to claim 2, wherein: the traveling wave head induction component is a voltage sensor arranged on the low-voltage side of the transformer.
5. The distributed power line fault location system based on dynamic measurement of traveling wave velocity according to claim 2, wherein: the remote data communication interface is connected with the microcontroller.
6. The distributed power line fault location system based on dynamic measurement of traveling wave velocity according to claim 2, wherein: the low-pass filter is a second-order low-pass filter.
7. The distributed power line fault location system based on dynamic measurement of traveling wave velocity according to claim 2, wherein: the high-precision time base module is a time base module with GNSS auxiliary time synchronization and is composed of a system clock and a GNSS clock.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110927520A (en) * | 2019-11-25 | 2020-03-27 | 山东理工大学 | Direct-current distribution line multi-end traveling wave fault positioning method and positioning device |
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| CN111551826A (en) * | 2020-06-18 | 2020-08-18 | 南京机电职业技术学院 | Reverse-traveling wave direct-current transmission line fault location method considering wave velocity change |
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| CN113219298B (en) * | 2021-03-24 | 2022-10-11 | 昆明理工大学 | Fault current traveling wave numerical simulation method for complex alternating current power grid |
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| CN112904155B (en) * | 2021-05-07 | 2024-02-02 | 武汉品迅科技有限公司 | Multi-branch dominant network fault pole tower stage positioning method |
| CN113884808B (en) * | 2021-09-28 | 2023-11-10 | 华北电力大学（保定） | Cable fault detection system and fault positioning method thereof |
| CN114325212A (en) * | 2021-11-11 | 2022-04-12 | 国网山东省电力公司东营供电公司 | Accurate fault positioning algorithm based on flexible monitoring of fault traveling wave |
| CN114397815B (en) * | 2021-12-14 | 2023-08-01 | 国网江苏省电力工程咨询有限公司 | Accurate screening and controlling method based on electric power pipe gallery and operation and maintenance monitoring system |
| CN114660401A (en) * | 2022-03-02 | 2022-06-24 | 云南电网有限责任公司电力科学研究院 | Power line fault positioning method and device, equipment and storage medium |
| CN115774229B (en) * | 2022-11-23 | 2023-12-12 | 深圳供电局有限公司 | Fault transient voltage traveling wave speed online verification method and system |
| CN117517877A (en) * | 2024-01-05 | 2024-02-06 | 江苏泽宇智能电力股份有限公司 | Distributed traveling wave online measurement fault positioning system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106959401A (en) * | 2017-03-24 | 2017-07-18 | 国网山东省电力公司 | A kind of distributed travelling wave ranging method |
-
2019
- 2019-06-10 CN CN201910497732.9A patent/CN110187235B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106959401A (en) * | 2017-03-24 | 2017-07-18 | 国网山东省电力公司 | A kind of distributed travelling wave ranging method |
Non-Patent Citations (1)
| Title |
|---|
| 基于分布式智能的小电流接地故障定位研究;孙桂花 等;中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑;正文第19页，第23-24页 * |
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