Disclosure of Invention
Aiming at the problem of low fault positioning accuracy in the prior art, the invention provides a tower-level positioning method for a fault of a multi-branch distribution network, which can realize accurate positioning of the tower-level of the fault.
In order to achieve the above purposes, the technical scheme is as follows:
a tower level positioning method for a multi-branch distribution network fault comprises the steps that the multi-branch distribution network comprises a distribution network line and a plurality of towers arranged on the distribution network line; the method comprises the following steps:
installing a plurality of fault monitoring devices on a multi-branch distribution network to collect traveling wave signals and current and voltage signals when faults occur, wherein each fault monitoring device is located near a unique tower, and the plurality of fault monitoring devices process the collected current and voltage signals to obtain a fault minimum interval;
processing to obtain the first time when the initial traveling wave reaches all fault monitoring equipment in the fault minimum interval according to the traveling wave signals received by all fault monitoring equipment in the fault minimum interval;
respectively taking each tower in the minimum fault interval as a simulated fault tower m, wherein m represents the number of the tower, m is more than or equal to 1, and m is a positive integer, and calculating second time for the initial traveling wave of the traveling wave signal generated by the simulated fault tower m to reach all the towers with the fault monitoring equipment nearby in the minimum fault interval;
and processing according to the first time and the second time to obtain an error square sum matrix, wherein the fault point is positioned near the tower corresponding to the minimum value of the error square sum.
Preferably, the multi-branch distribution network further comprises a plurality of line nodes arranged on the distribution network line, and the types of the line nodes comprise an on-pole switch and a power management unit;
the fault monitoring equipment is accessed to the multi-branch distribution network in a mode of accessing to distribution network lines and/or line nodes.
Preferably, the number of the fault monitoring devices is smaller than that of the towers, each fault monitoring device corresponds to a unique tower, and each fault monitoring device is arranged near the corresponding tower.
Preferably, the step of processing the collected current and voltage signals by the multiple fault monitoring devices to obtain the fault minimum interval is as follows:
the fault monitoring equipment processes the acquired current and voltage signals to obtain fault characteristic information, and processes the fault characteristic information to obtain a fault minimum interval;
the fault characteristic information includes short circuit information, grounding information, and disconnection information.
Preferably, based on the topological graph of the multi-branch distribution network, the types of the fault minimum intervals include double-ended intervals, T-connected intervals and multi-T-connected intervals.
Preferably, when a fault occurs, after collecting the first time when the traveling wave signal reaches all fault monitoring devices in the fault minimum interval, sorting all the first times according to the numbers of all the fault monitoring devices in the fault minimum interval to obtain a first sequence W1 … Wn, where n represents the number of all the fault monitoring devices in the fault minimum interval, n is greater than or equal to 2, and n is a positive integer.
Preferably, after the simulated fault tower m is preset, the distances D1 … Dn between the simulated fault tower m and all towers with fault monitoring equipment nearby in the fault minimum interval are calculated, n represents the number of all fault monitoring equipment in the fault minimum interval, n is greater than or equal to 2, and n is a positive integer.
Preferably, the second time for the initial traveling wave of the traveling wave signal generated by the simulated fault tower m to reach all the towers with the fault monitoring devices nearby in the fault minimum interval is calculated by the following formula:
Ti= Di/V
wherein,
i represents the number of the fault monitoring equipment in the fault minimum interval, i is more than or equal to 1, and i is a positive integer;
v represents the transmission speed of the traveling wave signal in the distribution network line;
di represents the distance between the simulated fault tower m and the tower with the ith fault monitoring device in the fault minimum interval;
and Ti represents the second time when the initial traveling wave of the traveling wave signal generated by the simulated fault tower m reaches the tower provided with the ith fault monitoring device in the fault minimum interval.
Preferably, after the simulated fault tower m is preset and a corresponding group of second time is obtained through calculation each time, the group of second time is sorted according to the numbers of all fault monitoring devices in the fault minimum interval to obtain a second sequence T1 … Tn;
after each tower in the minimum fault interval is preset as a simulated fault tower m, z groups of second sequences T1 … Tn are obtained, wherein z represents the number of all towers in the minimum fault interval, z is more than or equal to 2, and z is a positive integer.
Preferably, the error analysis is performed on all fault monitoring devices in the fault minimum interval respectively through the following formula to obtain the sum of squares of errors:
wherein,
i represents the ith fault monitoring equipment in the fault minimum interval;
n represents the number of all fault monitoring devices in the fault minimum interval;
y represents the sum of the squared errors of the fault monitoring devices.
The invention has the beneficial effects that: the problem of the arc hangs down, wave speed is not clear etc. and causes the fault location degree of accuracy not high is solved, realize that the tower type patrols the line is decided to the trouble, location fault point position that can be more accurate, can learn the fault point position the very first time behind the trouble, reduce trouble and seek and patrol time, reduce manpower and materials, reduce personnel intensity of labour by a wide margin and shorten power off time, reduce and receive the influence user number, improve economic benefits.
The error between the fault tower and the actual fault point calculated by the method is the span L, and the maximum error range of the fault tower from the fault point can be known to be
And the actual line span is generally about 50 to 60 meters, so that the error of the invention is about 25 to 30 meters. Compared with the traditional traveling wave positioning method, the method has great practical application advantages.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific examples described herein are intended to be illustrative only and are not intended to be limiting. Moreover, all other embodiments that can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort belong to the protection scope of the present invention.
The present invention will be described in further detail with reference to the accompanying drawings and examples.
As shown in fig. 1 and fig. 2, the invention discloses a tower level positioning method for a fault of a multi-branch distribution network, wherein the multi-branch distribution network comprises a distribution network line, a plurality of towers arranged on the distribution network line and a plurality of line nodes arranged on the distribution network line.
N fault monitoring devices are installed or embedded on a multi-branch distribution network in a distributed mode, when a fault occurs, z pole towers are determined in the fault minimum interval according to the change characteristics of electric parameters, the fault minimum interval comprises a plurality of edge pole towers located at the edge of the interval and a plurality of inner pole towers located inside the interval, and the total number of the edge pole towers and the inner pole towers is z. The method comprises the steps that a fault monitoring device is arranged near each edge tower (the distance between the fault monitoring device and the edge tower is set according to actual requirements), the edge towers and the fault monitoring devices are in one-to-one correspondence, the number of the edge towers and the number of the fault monitoring devices are N, each fault monitoring device is provided with a unique device number i, N is larger than or equal to N, z is larger than or equal to N, N is larger than or equal to i, and N, N and i are positive integers.
Collecting traveling wave signals on all fault monitoring devices in the fault minimum interval, recording the initial time when the traveling wave signals reach all fault monitoring devices in the fault minimum interval, and sequencing according to the serial numbers of the fault monitoring devices to obtain a first sequence W1 … Wn.
The method comprises the steps of presetting m poles and towers (whether fault monitoring equipment is arranged near the m poles and towers or not, namely z poles and towers in the fault minimum interval can be preset as simulated fault poles and towers m) in the fault minimum interval, calculating the initial time of a traveling wave signal generated by the simulated fault poles and towers m to all poles and towers (namely all edge poles and towers) in the fault minimum interval, and sequencing according to the serial numbers of the fault monitoring equipment to obtain a second sequence T1 … Tn, wherein the z groups of second sequences T1 … Tn can be finally obtained, wherein z is more than or equal to m, and m is a positive integer.
Based on all the first sequences W1 … Wn and the second sequences T1 … Tn, the sum of squares of monitoring errors of all fault monitoring devices in the fault minimum interval is analyzed, an error sum of squares matrix is obtained, the tower corresponding to the error sum of squares minimum is an actual fault tower, and a fault point is located nearby the actual fault tower.
In the embodiment, the accurate positioning technology is used as effective supplement of power distribution automation, the fault diagnosis and rapid positioning capabilities of the power distribution line are improved, the problem of low fault positioning accuracy caused by reasons such as sag, unclear wave speed and the like is solved, and fault tower-fixing type line patrol is realized. The position of location fault point that can be more accurate can learn the fault point the very first time after the trouble, solves the big scheduling problem of line patrol difficulty and fortune dimension intensity of labour that join in marriage net long-term existence, reduces the plenty of time of troubleshooting and tour, reduces manpower and materials, reduces personnel intensity of labour by a wide margin, shortens the power off time, reduces and is influenced the number of users, improves maintenance efficiency, improves economic benefits, provides technical support for distribution network emergency repair and guarantor power supply.
With continued reference to fig. 1 and 2, the tower level positioning method for the multi-branch distribution network fault includes:
step S1, installing a plurality of fault monitoring devices on the multi-branch distribution network to collect traveling wave signals and current and voltage signals when faults occur, and processing the collected current and voltage signals by the plurality of fault monitoring devices to obtain a fault minimum interval. Specifically, N fault monitoring devices are installed or embedded on the line, and the fault monitoring devices can be embedded into Power distribution network line nodes such as a column switch and a Power Management Unit (PMU), and can also be independently installed on the line in a distributed manner. And determining the fault minimum interval through fault information characteristics (the fault information characteristics can be short circuit, grounding or disconnection information characteristics). According to the distribution network multi-branch topological graph, the fault minimum interval can be a double-end interval, a T-connection interval or a multi-T-connection interval.
And step S2, processing to obtain the first time when the initial traveling wave reaches all fault monitoring devices in the fault minimum interval according to the traveling wave signals received by all fault monitoring devices in the fault minimum interval. Specifically, when a fault occurs, collecting fault initial traveling wave signals on all fault monitoring devices in a fault minimum interval, recording the time when the fault initial traveling wave signals reach all fault monitoring devices, and sequencing according to the serial numbers of the fault monitoring devices to obtain a first sequence W1 … Wn, wherein n represents the number of all fault monitoring devices in the fault minimum interval, n is greater than or equal to 2, and n is a positive integer.
And S3, respectively taking each tower in the minimum fault interval as a simulated fault tower m, and calculating second time for the initial traveling wave of the traveling wave signal generated by the simulated fault tower m to reach all edge towers in the minimum fault interval, wherein m is more than or equal to 1 and is a positive integer. Specifically, all towers in the minimum fault interval are traversed (whether fault monitoring equipment is installed or not), the tower with the fault is preset to be a tower number m, and the preset tower with the simulated fault m can be all towers in the minimum fault interval. And calculating the distances D1 … Dn from the m-number tower to all edge towers in the minimum fault interval, wherein n is more than or equal to 2 and is a positive integer. And calculating the time of the fault reaching all the edge towers in the fault minimum interval according to the distance and the wave speed, and sequencing according to the serial numbers of the fault monitoring equipment near all the edge towers to obtain a second sequence T1 … Tn, wherein n is more than or equal to 2, and n is a positive integer.
And step S4, processing according to the first time and the second time to obtain an error square sum matrix, wherein the fault point is located near the tower corresponding to the minimum error square sum. Specifically, a fault point is judged in advance to be near the mth tower in the minimum fault interval, an error sum of squares matrix is obtained based on the sum of squares analysis of monitoring errors of all fault monitoring equipment in the minimum fault interval, the tower corresponding to the minimum error sum of squares is the fault tower, and the fault point is located near the fault tower.
Furthermore, the number of the fault monitoring devices is far smaller than that of the towers, each fault monitoring device corresponds to a unique tower, and each fault monitoring device is arranged in a preset distance range near the corresponding tower.
Further, the specific steps of processing the collected current and voltage signals by the multiple fault monitoring devices to obtain the fault minimum interval are as follows:
and the fault monitoring equipment processes the acquired current and voltage signals to obtain fault characteristic information and processes the fault characteristic information to obtain a fault minimum interval.
The fault signature information includes short circuit information, ground information, and disconnection information.
Further, after the simulated fault tower m is preset, calculating the distances D1 … Dn between the simulated fault tower m and all edge towers in the fault minimum interval, and calculating the second time for the initial traveling wave of the traveling wave signal generated by the simulated fault tower m to reach all edge towers in the fault minimum interval by the following formula:
Ti= Di/V,
wherein,
and i represents the number of the fault monitoring equipment in the fault minimum interval, wherein i is more than or equal to 1, and i is a positive integer.
And V is used for representing the transmission speed of the traveling wave signal in the distribution network line.
Di represents the distance between the simulated fault tower m and the edge tower near the fault minimum interval and provided with the ith fault monitoring equipment;
and Ti represents the second time when the initial traveling wave of the traveling wave signal generated by the simulated fault tower m reaches the edge tower which is provided with the ith fault monitoring equipment and is near the fault minimum interval.
Further, after the simulated fault tower m is preset and a corresponding group of second time is obtained through calculation each time, the group of second time is sorted according to the numbers of all fault monitoring devices in the fault minimum interval to obtain a second sequence T1 … Tn.
After each tower in the minimum fault interval is preset as a simulated fault tower m, z groups of second sequences T1 … Tn are obtained, wherein z represents the number of all towers in the minimum fault interval, z is more than or equal to 2, and z is a positive integer.
Further, the error analysis is respectively carried out on all fault monitoring devices in the fault minimum interval through the following formula to obtain the sum of squares of errors:
wherein,
i is used for representing the ith fault monitoring device in the fault minimum interval.
n is used to represent the number of all fault monitoring devices within the fault minimum interval.
Y is used to represent the sum of the squares of the errors of the fault monitoring devices. The Y value can be regarded as the deviation from the real fault tower, and the smaller the deviation is, the more the real fault tower is.
Specifically, all towers in the minimum fault interval determined by the fault monitoring equipment can be simulated fault towers m, if the number of all towers in the minimum fault interval is z, z times of error square sum calculation is carried out on all towers in the minimum fault interval, after an error square sum sequence Y of the towers is obtained and is not ([ Y1Y2Y3 … Ym … Yz ], the sizes are compared, the smallest tower is the fault tower, and a fault point is determined to be near the tower corresponding to the minimum value of the Y value.
With continued reference to fig. 1 and 2, in a specific embodiment, the method for positioning the tower level with the fault of the multi-branch distribution network includes the following steps:
and 10 fault monitoring devices are installed on the multi-branch distribution network.
The method includes the steps that current and voltage information collected by 10 fault monitoring devices is processed to obtain fault characteristic information, a fault minimum interval is determined according to the fault characteristic information, according to the distribution network multi-branch topological graph in the embodiment, the fault minimum interval is a T-connection interval, namely the fault minimum interval is located among a main line No. 2 tower, a main line No. 82 tower and an xx branch line No. 22 tower. The tower with the main line 2, the tower with the main line 82 and the tower with the xx branch line 22 are edge towers, and the other towers among the tower with the main line 2, the tower with the main line 82 and the tower with the xx branch line 22 are inner towers. The number of all fault monitoring devices in the minimum fault region is 3, and the fault monitoring devices are respectively arranged near a main line No. 2 tower, a main line No. 82 tower and an xx branch line No. 22 tower. The fault information characteristic may be a short circuit, ground or wire break information characteristic.
When a fault occurs, collecting traveling wave signals on all fault monitoring devices in a fault minimum interval, recording the first time when the fault initial traveling wave signals reach all fault monitoring devices in the fault minimum interval, and sequencing to obtain a first sequence W1 … W3.
Traversing all towers in the minimum fault interval, presetting the tower with the simulated fault as a tower number m, and enabling the tower with the simulated fault m to be all towers in the minimum fault interval.
Calculating the distances D1 … D3 of all towers (namely, towers with fault monitoring equipment nearby, such as a main line 2# tower, a main line 82 number tower and an xx branch line 22 number tower) with fault monitoring equipment nearby in the m-distance fault tower fault minimum interval, calculating the time from the distance and the wave speed until the initial traveling wave reaches all towers with fault monitoring equipment nearby in the fault minimum interval, namely second time, and sequencing the second time to obtain a second sequence T1 … T3.
And prejudging that the fault point is near the m-th tower in the minimum fault interval, and obtaining an error square sum matrix based on the square sum analysis of detection errors of all fault monitoring equipment in the minimum fault interval, wherein the tower corresponding to the minimum error square sum is the fault tower, so that the fault point is judged to be near the fault tower. The square sum of the monitoring errors of the fault monitoring equipment is calculated according to the following formula, the value can be regarded as the deviation from the real fault tower, and the smaller the deviation is, the more the real fault tower is:
m is the m-th tower in the minimum fault interval, i is used for representing the ith fault monitoring equipment in the minimum fault interval, and Ym is used for representing the error square sum of the monitoring errors of the m-th tower in the minimum fault interval.
According to the embodiment of the invention, as shown in fig. 1, a schematic diagram of a multi-branch distribution network line is shown, if the number of all towers in a minimum fault interval is z, z times of error square sum calculation is performed on all towers in the minimum interval, so that an error square sum sequence Y = [ Y1Y2Y3 … Ym … Yz ] of the towers is obtained, and the smallest tower is the fault tower by comparison. And judging that the fault point is near the tower corresponding to the minimum value of the Y value.
In summary, according to the tower-level positioning method for the multi-branch distribution network fault, N fault monitoring devices are installed or embedded in a line in a distributed manner, when a fault occurs, a fault minimum interval is determined by using the change characteristics of electrical parameters, traveling wave signals on all fault monitoring devices in the fault minimum interval are collected, and the time when the traveling wave signals reach the fault monitoring devices is recorded and sequenced. The method comprises the steps of prejudging a tower number m of a fault in a fault minimum interval, obtaining a square sum matrix of errors based on square sum analysis of detection errors of all fault monitoring equipment in the fault minimum interval, enabling the tower corresponding to the error square sum minimum to be a fault tower, enabling a fault point to be located near the fault tower, solving the problem that the fault location accuracy is not high due to problems of sag, unclear wave speed and the like, and achieving fault tower type line patrol.
The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.