CA2325101C - Method of calculating surge propagation speed and system for locating fault points by the use thereof - Google Patents
Method of calculating surge propagation speed and system for locating fault points by the use thereof Download PDFInfo
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- CA2325101C CA2325101C CA002325101A CA2325101A CA2325101C CA 2325101 C CA2325101 C CA 2325101C CA 002325101 A CA002325101 A CA 002325101A CA 2325101 A CA2325101 A CA 2325101A CA 2325101 C CA2325101 C CA 2325101C
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
An object of the present invention is to provide a means for accurately locating fault points by calculating the surge propagation speed at the time of surge identification. The present invention includes a method of calculating surge propagation speed in a fault point location system comprising: substations [1] installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station [2]; and the master station [2] for locating a fault point on the basis of the surge detection time information; characterized in that the surge propagation speed is obtained on the basis of detection times of a surge voltage or a surge current at the first substation positioned adjacent to a fault point along the transmission and distribution line and another substation positioned next to the first substation together with a length of the transmission and distribution line between the first and other substations. Based on the distance between substations [1A and 1B] and the difference of surge propagation time, the surge propagation speed v AB can be computed. Therefore, the surge propagation speed v AB that is obtained can be used as the surge propagation speed v which will be used for identifying the location of the fault point [P]. Moreover, such surge propagation speed is used to identify the location of a fault point, therefore enabling an accurate fault point location under varying conditions such as of transmission and distribution line or weather.
Description
METHOD OF CALCULATING SURGE PROPAGATION SPEED AND SYSTEM FOR
LOCATING FAULT POINTS BY THE USE THEREOF
BACKGROUND OF THE INVENTION
The present invention relates to a method of calculating surge propagation speed and a fault point location system. More particularly, the present invention relates to a method to calculate surge propagation speed at the time of locating a surge and a fault point locating system which is able to accurately identify a fault point by obtaining the surge propagation speed at the time of locating a surge.
Heretofore, when a fault occurs along the way of a power transmission line and distribution line (hereinafter designated a "transmission and distribution line" for both lines), a method is known by which the fault point on the transmission and distribution line is determined in accordance with a difference in surge detection time at two substations situated across the fault point (Japanese Patent Publication No. 51274 of 1988, etc.) In the foregoing method, a fault location is identified based on the times at which a surge is detected at each of the two substations, the distance between the two substations, and the speed at which the surge propagates in the transmission and distribution line (hereinafter designated the "surge propagation speed" ) .
The surge propagation speed changes due to conditions of the transmission and distribution line per se (e.g. differences in overhead distribution lines or distribution cables, differences in ground resistance rates, etc.), weather conditions, and so on.
For this reason, in many of the prior art methods of location, values of surge propagation speed that were obtained beforehand by actual measurements were used as estimate values. Providing that the distances between substations were short, the errors introduced by performing fault point location with such estimated values were regarded as negligible in many cases.
SUMMARY OF THE INVENTION
Depending on the conditions of transmission and distribution line or weather, the differences between the values of surge propagation speed at the time of surge identification and those of the estimated surge propagation speed were so large that , in some cases, the errors in surge identification were no longer negligible. In addition, if the distances between substations were long, the errors in surge identification were no longer negligible in some cases.
It is therefore an object of the present invention to provide a method of calculating surge propagation speed which derives the surge propagation speed at the time of surge identification. Another object of the present invention is to provide a fault point location system which accurately identifies fault locations by obtaining accurate surge propagation speeds.
A method of calculating surge propagation speed expressed in the first aspect of the invention is a method of calculating surge propagation speed in a fault point location system comprising:
substations 1 installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station 2; and
LOCATING FAULT POINTS BY THE USE THEREOF
BACKGROUND OF THE INVENTION
The present invention relates to a method of calculating surge propagation speed and a fault point location system. More particularly, the present invention relates to a method to calculate surge propagation speed at the time of locating a surge and a fault point locating system which is able to accurately identify a fault point by obtaining the surge propagation speed at the time of locating a surge.
Heretofore, when a fault occurs along the way of a power transmission line and distribution line (hereinafter designated a "transmission and distribution line" for both lines), a method is known by which the fault point on the transmission and distribution line is determined in accordance with a difference in surge detection time at two substations situated across the fault point (Japanese Patent Publication No. 51274 of 1988, etc.) In the foregoing method, a fault location is identified based on the times at which a surge is detected at each of the two substations, the distance between the two substations, and the speed at which the surge propagates in the transmission and distribution line (hereinafter designated the "surge propagation speed" ) .
The surge propagation speed changes due to conditions of the transmission and distribution line per se (e.g. differences in overhead distribution lines or distribution cables, differences in ground resistance rates, etc.), weather conditions, and so on.
For this reason, in many of the prior art methods of location, values of surge propagation speed that were obtained beforehand by actual measurements were used as estimate values. Providing that the distances between substations were short, the errors introduced by performing fault point location with such estimated values were regarded as negligible in many cases.
SUMMARY OF THE INVENTION
Depending on the conditions of transmission and distribution line or weather, the differences between the values of surge propagation speed at the time of surge identification and those of the estimated surge propagation speed were so large that , in some cases, the errors in surge identification were no longer negligible. In addition, if the distances between substations were long, the errors in surge identification were no longer negligible in some cases.
It is therefore an object of the present invention to provide a method of calculating surge propagation speed which derives the surge propagation speed at the time of surge identification. Another object of the present invention is to provide a fault point location system which accurately identifies fault locations by obtaining accurate surge propagation speeds.
A method of calculating surge propagation speed expressed in the first aspect of the invention is a method of calculating surge propagation speed in a fault point location system comprising:
substations 1 installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station 2; and
2 the master station 2 for locating a fault point on the basis of the surge detection time information;
characterized in that the surge propagation speed is obtained on the basis of the detection times of a surge current or a surge voltage at the first substation positioned adjacent to a fault point along the transmission and distribution lines and another substation positioned next to the first substation together with a length of the transmission and distribution lines between the first and other substations.
The fault point location system expressed in the second aspect of the invention is a fault point location system comprising:
substations 1 installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station 2; and the master station 2 for locating a fault point on the basis of the surge detection time information;
characterized in that: each of the substations 1, that functions as a clock, is capable of receiving radio waves from a global positioning system (GPS) satellite and identifying the time held by the GPS satellite to synchronize its own time with the time held by the GPS satellite, detects surge currents or surge voltages occurring along the transmission and distribution lines in which the particular substation 1 is installed, determines the surge detection time at which the surge current or surge voltage is detected, and transfers the surge detection time to the master station 2 through a communication network; the master station 2 receives the surge detection time from the substation 1 via the communication network, identifies the
characterized in that the surge propagation speed is obtained on the basis of the detection times of a surge current or a surge voltage at the first substation positioned adjacent to a fault point along the transmission and distribution lines and another substation positioned next to the first substation together with a length of the transmission and distribution lines between the first and other substations.
The fault point location system expressed in the second aspect of the invention is a fault point location system comprising:
substations 1 installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station 2; and the master station 2 for locating a fault point on the basis of the surge detection time information;
characterized in that: each of the substations 1, that functions as a clock, is capable of receiving radio waves from a global positioning system (GPS) satellite and identifying the time held by the GPS satellite to synchronize its own time with the time held by the GPS satellite, detects surge currents or surge voltages occurring along the transmission and distribution lines in which the particular substation 1 is installed, determines the surge detection time at which the surge current or surge voltage is detected, and transfers the surge detection time to the master station 2 through a communication network; the master station 2 receives the surge detection time from the substation 1 via the communication network, identifies the
3 location where a fault has occurred on the transmission and distribution line based on the difference of the surge detection times from two of the substations 1 positioned at each end of the fault section, the length of the transmission and distribution line of the fault section, and the surge propagation speed; and the surge propagation speed is obtained on the basis of the surge detection times at the first substation positioned adjacent to a fault point along the transmission and distribution lines and another substation positioned next to the first substation together with the length of the transmission and distribution lines between the first and other substations.
The master station 2, as indicated in the third Claim of the invention, uses the surge detection time tl at the first of a pair of substations situated across the fault point along the transmission and distribution lines, the surge detection time t2 at the other substation of the pair, the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the first substation to the fault point along the transmission and distribution line according to the equation L1 = (L + (tl -t2) x v) / 2.
Furthermore, the master station 2, as indicated in the fourth aspect of the invention: uses the surge detection time tl at a substation closest to the source-side end of the transmission and distribution line, the surge detection time t2 at a substation positioned at the far end of the transmission and distribution line, the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the substation closest to the source-side end to
The master station 2, as indicated in the third Claim of the invention, uses the surge detection time tl at the first of a pair of substations situated across the fault point along the transmission and distribution lines, the surge detection time t2 at the other substation of the pair, the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the first substation to the fault point along the transmission and distribution line according to the equation L1 = (L + (tl -t2) x v) / 2.
Furthermore, the master station 2, as indicated in the fourth aspect of the invention: uses the surge detection time tl at a substation closest to the source-side end of the transmission and distribution line, the surge detection time t2 at a substation positioned at the far end of the transmission and distribution line, the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the substation closest to the source-side end to
4 the fault point along the transmission and distribution line according to the equation Ll = (L +(tl - t2) x v) / 2; and further uses the surge detection time t3 at the first of a pair of substation situated across the fault point found as per the calculation above, the surge detection time t4 at the other substation of the pair, the surge propagation speed v, and the length L' of the transmission and distribution line between the pair of substations to obtain the distance L3 from the first substation to the fault point along the transmission and distribution line according to the equation L3 =(L' + (t3 - t4) X v) / 2.
As per the method, calculating surge propagation speed of the first aspect of the invention and a fault point location system of the second aspect of the invention, surge propagation speed at the time of surge identification is found and then the surge propagation speed is used in identifying a fault point. It is possible to obtain the accurate location of fault points even under varying conditions such as of the transmission and distribution line and weather, etc.
In a fault point location system of the third and the fourth aspect of the invention, because of the provision of a master station in the system, it is possible for the master station to identify a fault point based on surge detection time information from each substation. Additionally, by providing a master station which is separate from any substations and which is installed on the transmission and distribution lines and has the responsibility of locating fault points to the equipment of the master station, it is possible for each substation to be compact and easy to install.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an explanatory diagram showing the relationship between a master station and substations.
Fig. 2 is an explanatory diagram illustrating components of a substation.
Fig. 3 is an explanatory diagram illustrating components of a master station.
Fig. 4 is an explanatory diagram of the principle of identifying fault points.
Fig. 5 is a diagrammatic representation for explaining the method of determining the surge propagation speed.
Fig. 6 is a diagrammatic representation for explaining the method of determining the surge propagation speed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be explained below by referring to Fig. 1 through Fig. 6.
(1) The configuration of the fault point location system.
As shown in Fig. 1, the fault point location system of an embodiment of the present invention comprises:
substations 1 which are installed at each steel tower or pole along transmission and distribution lines and a master station 2 which is installed at a service office or branch office of a power company and which identifies points of fault on the basis of information from substations 1.
(a) Substations As shown in Fig. 2, a substation 1 is provided with a GPS
antenna 111, a GPS receiver 112, an oscillator 121, a reference clock 122, a time synchronization correcting circuit 123, a zero-phase current transformer (ZCT) 131, a filter circuit 132, a surge signal detection circuit 133, a surge detection time holding circuit 134, a central processing unit 141, and a communication interface 142.
The ZCT 131, the filter circuit 132, the surge signal detection circuit 133, the surge detection time holding circuit 134, and a part of the central processing unit 141 correspond to a "surge detection means 13". Additionally, the central processing unit 141 and the communication interface 142 correspond to a "surge information transmitting means 14b".
Further in a likewise concept, the GPS antenna 111 and the GPS receiver 112 together can be regarded as a "GPS receiving means 11" and the oscillator 121, the reference clock 122, and the time synchronization correcting circuit 123 together can be considered as a"time measuring means 12".
Each component will be explained below.
(i) ZCT 131 The ZCT 131 is mounted to the steel tower of a transmission and distribution line to detect surge signals (surge currents) that occur at the time of a fault and then send them to the filter circuit 132. If surge voltages are to be detected as surge signals, a voltage detector such as a PT or PD will be used.
(ii) Filter circuit 132 The filter circuit 132 filters signals, which the sensor 131 has detected, to remove unnecessary commercial frequency components that are not surge signals and allows only the surge signals to pass through and are sent to the surge signal detection circuit 133.
(iii) Surge signal detection circuit 133 The surge signal detection circuit 133 detects the level of a surge signal and then determines that a surge occurred if the signal level exceeds a surge-acknowledging level, whereupon outputting a time holding signal to the surge detection time holding circuit 134.
(iv) Surge detection time holding circuit 134 At the time when a time holding signal is output from the surge signal detection circuit 133, the surge detection time holding circuit 134 holds the time of the reference clock 122 and outputs it as the surge detection time to the central processing unit 141.
(v) GPS antenna 111 and GPS receiver 112 The GPS antenna 111 receives radio waves from a GPS
satellite and send them to the GPS receiver 112. Then, the GPS
receiver 112 extracts, as a synchronization signal, the information of the standard time held by the GPS satellite from the radio waves and then outputs the signal to the time synchronization correcting circuit 123.
(vi) Time synchronization correcting circuit 123 In accordance with the synchronization signal that is output by the GPS receiver 112, the time synchronization correcting circuit 123 synchronizes the time of the reference clock 122 with the standard time held by the GPS satellite.
(vii) Reference clock 122 The reference clock 122 outputs the reference time to the surge detection time holding circuit 134.
(viii) Oscillator 121 The oscillator 121 outputs the reference time signal for measuring the time to the reference clock 122.
(ix) Central processing unit 141 The central processing unit 141 sends the surge detection time that is output by the surge detection time holding circuit 134 to the master station 2 via the communication interface 142.
(x) Communication interface 142 The communication interface 142 relays communication signals between the central processing unit 141 and the commercial telephone network so that the central processing unit 141 can communicate with the master station 2 using the public data network.
(b) Master station As shown in Fig. 3, a master station 2 comprises a communication interface 21, an auxiliary storage unit 222, a central processing unit 23, a CRT 241, a printer 242, and a keyboard 25.
The communication interface 21 can be regarded as a "substation surge information receiving means 21b".
Likewise, the central processing unit 23 can be regarded as a "fault location identifying means 23c" which identifies fault locations based on the surge detection time and surge propagation speed.
The central processing unit 23 also can be regarded as a V%surge propagation speed calculation means 23d" which calculates surge propagation speed based on the surge detection time.
Reference character 21a is substation location information receiving means, reference character 22 is map information storage means, and reference character 23a is transmission and distribution line map information preparing means.
Further, the cathode ray tube (CRT) 241 and the printer 242 can be regarded as "information output means 24" which output the results of fault location. The keyboard 25 as an "input means".
Each component will be explained below.
(i) Communication interface 21 The communication interface 21 relays communication signals to and from the substations 1. Precisely, it converts signals transmitted from the substations 1 via a public data network to supply them to the central processing unit 23.
(ii) Central processing unit 23 (a personal computer, a workstation, etc.) The central processing unit 23 receives the location information and the surge detection time, which are transmitted by each substation 1, via the communication interface 21, and performs the fault point location processing, which will be described later.
Fault points obtained by processing the fault point location is output to the CRT 241 or the printer 242 together with transmission and distribution line map data stored in the auxiliary storage unit 222.
(iii) Auxiliary storage unit 222 (a hard disk, etc.) The auxiliary storage unit 222 stores the surge detection time and the location information transmitted by each substation 1, the fault points calculated by the central processing unit 23, and the transmission and distribution line map data necessary for the central processing unit 23 to perform processing.
The transmission and distribution line map data includes such data as the locations of poles and steel towers, and the distances between the poles (steel towers), etc.
(iv) Printer 242 Following the command by the central processing unit 23, the printer 242 prints out a transmission and distribution line map data or the results of fault location, which are sent by the central processing unit 23.
(v) CRT 241 Following the command of the central processing unit 23, the CRT 241 displays a transmission and distribution line map or the results of fault location, which are sent by the central processing unit 23.
(vi) Keyboard 25 (input means) The keyboard 25 is used to input drawing data, etc.
necessary for creating transmission and distribution line maps.
The drawing data outputs such data as the locations of poles and steel towers, and the distances between the poles (steel towers), etc.
(2) Processing of surge propagation speed calculation.
The calculation method for surge propagation speed processed by the surge propagation speed calculation means 23d will be explained below. When a fault occurs many possible configurations of transmission and distribution lines can be considered but they can be categorized into cases (a) and (b) below.
(a) In the case where substations are positioned on a straight line as shown in Fig. 5, substations 1A, 1B, 1C are installed in such an order on a piece of transmission and distribution line and a fault occurs at the point P between substations 1B and 1C.
When a surge is caused because of a fault, the surge propagates along the transmission and distribution line from the fault point P to and through the substations 1C, 1B, and 1A in the said order. For this reason, if the distance LõB between the substations 1A and 1B is given, the surge propagation speed võ,, between the substations 1A and 1B can be computed Formula (1) shown below.
vAB = LAU ...
tA-ta vAB : surge propagation speed between the substations 1A and 1B
L,O distance between the substations 1A and 1B
t,, : surge propagation time at the substation 1A
tg : surge propagation time at the substation 1B
(b) In the case where substations are positioned on branched lines as shown in Fig. 6, a branch-off point R is introduced on the transmission and distribution line with substations 1D, 1E, and iF positioned on each of the branched pieces of transmission and distribution line and a fault occurs at the point P between the branch-off point R and the substation 1F.
When a surge is caused because of a fault, the surge propagates along the transmission and distribution lines from the fault point P to and through the substations 1F, as well as the branch-off point R, and substations 1D and 1E. At this time, if the distance L,, between the substation 1D and the branch-off point R and the distance L,, between the substation 1E and the same are found and the two distances L,, and LR, are not equal, speed v.E of the surge propagating from the branch-off point R to both substations 1D and 1E can be computed according to Formula (2) shown below.
Further, the sections between the branch-off point R, for which the surge propagation speed vRDE is determined when the substations 1D, 1E are adjacent to the section, which includes the fault point P, between the branch-off point R and the substation 1F, and the conditions of transmission and distribution lines, as well as the weather conditions, are found to be similar. For this reason, the surge propagation speed vRDF, can be regarded as a close approximation of the surge propagation speed vRF between the branch-off point R and the substation iF.
Therefore, the surge propagation speed v.E that is obtained can be used as the surge propagation speed v which will be used for identifying the location of the fault point P.
v _ (Lnx~'LRr) (LEx~'Lxp) _LnR-L~ ...~2) RDB -tD _ tE tD _ tE
vjwE : surge propagation speed between the branch - off point R and the substations 1A and 1B
LDR : distance between the substations 1D and the branch - off point R
Lm : distance between the substations 1E and the branch - off point R
Lm : distance between the branch - off point R and the fault point P
tD : surge propagation time at the substation 1D
tE : surge propagation time at the substation 1E
By processing the calculation of surge propagation speed according to the aforesaid method for surge propagation speed to accurately determine the surge propagation speed v at the time of fault point location, errors in the location of fault points can be reduced.
(3) Processing in the fault point location system Procedures for identifying the location of a fault when one occurs on the transmission and distribution line will be explained below. First, determination of the surge detection time by a substation will be explained in the paragraphs under (a), which is followed by the explanation of fault point location by the master station in the paragraphs under (b).
(a) Determination of a surge detection time by a substation.
The procedure for determining a surge detection time by the central processing unit 141 of a substation 1 will be explained below.
A substation receives surge currents that occur at the time of a fault with the ZCT 131, detects the surge currents with the filter circuit 132 and the surge signal detection circuit 133, and outputs a surge detection signal to the surge detection time holding circuit 134. The substation, then, holds the reference time at which a surge detection signal is received in the surge detection time holding circuit 134, and outputs the reference time to the central processing unit 141 as a surge detection time, followed by the central processing unit 141 which automatically transfers the data of the detection time of the surge detection signal together with the substation number to the master station as fault information.
(b) Fault point location by the master station.
An explanation of the principle and the procedures of locating a fault point performed by the central processing unit 23 of the master station 2 will be provided below. First the principle of locating a fault point will be explained in the paragraphs under (i), and subsequently the procedures of locating a fault point will be explained in the paragraphs under (ii).
(i) Principle of locating a fault point A diagram of the principle of locating a fault point is provided in Fig. 4.
Occurrence of a ground fault within the section between substations (1) and (2) causes a travelling wave (a surge) to develop as shown in Fig. 4. The length of time required for detecting this travelling wave at substations O and is proportional to distance L1 and L2 from the point where the fault has occurred to each substation assuming that the propagation speed v of the travelling wave propagating along the transmission and distribution line is constant.
That is, if the distance L between substations (1) and and the propagation speed v of the travelling wave are known and the difference in the length of time detected at substations and is accurate, the equation "L1 = (L +(tl - t2) x v) / 2", shown in Fig. 4, allows for determination of the distance L1 from the substation (1) to the fault point.
"Propagation speed v of the travelling wave" at the time of fault point location can be determined according to the aforementioned processing of surge propagation speed calculation.
In the fault point location system of the present embodiment, the length L of a transmission and distribution line segment between substations (positioned at the source side and the end of the transmission and distribution line) which examine surge detection time differences is determined by calculation and stored in memory beforehand. This length L may be either manually input or determined by a means such as automated measurement utilizing GPS.
In addition, under the assumption that the transmission distribution line segment between substations adjacent to each other is almost straight, the positional information of both substations (longitude, latitude, and altitude) can be used to calculate the length of the transmission and distribution line segment between the two substations.
For the length of the transmission and distribution line across substations not adjacent to each other, adding each line segment between any two adjacent substations that exist between the first two substations provides the target length L.
(ii) Procedure of locating a fault point The central processing unit 23 of the master station 2, in advance, calculates and stores in memory the length L of transmission and distribution line between the substation closest to the source-side end and each substations positioned at each end of the transmission and distribution network.
Then the central processing unit 23 selects a combination of the substation 1 closest to the source-side end of the transmission and distribution line and another substation 1 closest to the ends of the trunk line and the spur lines to locate a fault point based on the difference in surge detection times at both substations.
That is, the central processing unit 23 uses a surge detection time tl at a substation on the source side, a surge detection time t2 at a substation positioned at the far end of the transmission and distribution line, surge propagation speed v, and the length L of the transmission and distribution line between the two substations to obtain the distance L1 from the substation on to the source side to the location where a fault occurred along the transmission and distribution line according to the equation L1 = (L +(tl - t2) x v) / 2.
Then, if further substations 1 are found near and across the located fault point, the reliability of the fault point location can be increased by locating the fault point again based on the difference of surge detection times at these substations.
Such a procedure of locating a fault point may be executed by an operator manually inputting necessary information for the central processing unit 23 every time a fault point location is performed or a software program may be created so that the central processing units 23 automatically handles the processing.
In this procedure, an accurate time difference will not be obtained unless the reference time at the substation on each side has been synchronized with each other, wherein, as described above, time at each substation is synchronized to correct at any time by synchronizing the reference time at each substation with the reference time sent from a GPS satellite.
(iii) Displaying a fault location The central processing unit 23 of the master station 2, after identifying a fault point location, displays transmission and distribution line map information which is stored in the auxiliary storage unit 222 and the located fault point on the screen of the CRT 241 in order to notify the operator of the location of fault occurrence. Additionally, it causes the printer 242 to print out such information according to the operators command.
(4) Operating the fault point location system Substations 1 will be mounted on poles (steel towers) supporting transmission and distribution lines and operated continuously 24 hours a day so that a fault can be detected at any time.
Master station 2 may be installed, for example, at a service office or branch office of a power company and operated only while an operator is available or 24 hours a day to quickly identify a fault point whenever a fault occurs.
As per the method, calculating surge propagation speed of the first aspect of the invention and a fault point location system of the second aspect of the invention, surge propagation speed at the time of surge identification is found and then the surge propagation speed is used in identifying a fault point. It is possible to obtain the accurate location of fault points even under varying conditions such as of the transmission and distribution line and weather, etc.
In a fault point location system of the third and the fourth aspect of the invention, because of the provision of a master station in the system, it is possible for the master station to identify a fault point based on surge detection time information from each substation. Additionally, by providing a master station which is separate from any substations and which is installed on the transmission and distribution lines and has the responsibility of locating fault points to the equipment of the master station, it is possible for each substation to be compact and easy to install.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an explanatory diagram showing the relationship between a master station and substations.
Fig. 2 is an explanatory diagram illustrating components of a substation.
Fig. 3 is an explanatory diagram illustrating components of a master station.
Fig. 4 is an explanatory diagram of the principle of identifying fault points.
Fig. 5 is a diagrammatic representation for explaining the method of determining the surge propagation speed.
Fig. 6 is a diagrammatic representation for explaining the method of determining the surge propagation speed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be explained below by referring to Fig. 1 through Fig. 6.
(1) The configuration of the fault point location system.
As shown in Fig. 1, the fault point location system of an embodiment of the present invention comprises:
substations 1 which are installed at each steel tower or pole along transmission and distribution lines and a master station 2 which is installed at a service office or branch office of a power company and which identifies points of fault on the basis of information from substations 1.
(a) Substations As shown in Fig. 2, a substation 1 is provided with a GPS
antenna 111, a GPS receiver 112, an oscillator 121, a reference clock 122, a time synchronization correcting circuit 123, a zero-phase current transformer (ZCT) 131, a filter circuit 132, a surge signal detection circuit 133, a surge detection time holding circuit 134, a central processing unit 141, and a communication interface 142.
The ZCT 131, the filter circuit 132, the surge signal detection circuit 133, the surge detection time holding circuit 134, and a part of the central processing unit 141 correspond to a "surge detection means 13". Additionally, the central processing unit 141 and the communication interface 142 correspond to a "surge information transmitting means 14b".
Further in a likewise concept, the GPS antenna 111 and the GPS receiver 112 together can be regarded as a "GPS receiving means 11" and the oscillator 121, the reference clock 122, and the time synchronization correcting circuit 123 together can be considered as a"time measuring means 12".
Each component will be explained below.
(i) ZCT 131 The ZCT 131 is mounted to the steel tower of a transmission and distribution line to detect surge signals (surge currents) that occur at the time of a fault and then send them to the filter circuit 132. If surge voltages are to be detected as surge signals, a voltage detector such as a PT or PD will be used.
(ii) Filter circuit 132 The filter circuit 132 filters signals, which the sensor 131 has detected, to remove unnecessary commercial frequency components that are not surge signals and allows only the surge signals to pass through and are sent to the surge signal detection circuit 133.
(iii) Surge signal detection circuit 133 The surge signal detection circuit 133 detects the level of a surge signal and then determines that a surge occurred if the signal level exceeds a surge-acknowledging level, whereupon outputting a time holding signal to the surge detection time holding circuit 134.
(iv) Surge detection time holding circuit 134 At the time when a time holding signal is output from the surge signal detection circuit 133, the surge detection time holding circuit 134 holds the time of the reference clock 122 and outputs it as the surge detection time to the central processing unit 141.
(v) GPS antenna 111 and GPS receiver 112 The GPS antenna 111 receives radio waves from a GPS
satellite and send them to the GPS receiver 112. Then, the GPS
receiver 112 extracts, as a synchronization signal, the information of the standard time held by the GPS satellite from the radio waves and then outputs the signal to the time synchronization correcting circuit 123.
(vi) Time synchronization correcting circuit 123 In accordance with the synchronization signal that is output by the GPS receiver 112, the time synchronization correcting circuit 123 synchronizes the time of the reference clock 122 with the standard time held by the GPS satellite.
(vii) Reference clock 122 The reference clock 122 outputs the reference time to the surge detection time holding circuit 134.
(viii) Oscillator 121 The oscillator 121 outputs the reference time signal for measuring the time to the reference clock 122.
(ix) Central processing unit 141 The central processing unit 141 sends the surge detection time that is output by the surge detection time holding circuit 134 to the master station 2 via the communication interface 142.
(x) Communication interface 142 The communication interface 142 relays communication signals between the central processing unit 141 and the commercial telephone network so that the central processing unit 141 can communicate with the master station 2 using the public data network.
(b) Master station As shown in Fig. 3, a master station 2 comprises a communication interface 21, an auxiliary storage unit 222, a central processing unit 23, a CRT 241, a printer 242, and a keyboard 25.
The communication interface 21 can be regarded as a "substation surge information receiving means 21b".
Likewise, the central processing unit 23 can be regarded as a "fault location identifying means 23c" which identifies fault locations based on the surge detection time and surge propagation speed.
The central processing unit 23 also can be regarded as a V%surge propagation speed calculation means 23d" which calculates surge propagation speed based on the surge detection time.
Reference character 21a is substation location information receiving means, reference character 22 is map information storage means, and reference character 23a is transmission and distribution line map information preparing means.
Further, the cathode ray tube (CRT) 241 and the printer 242 can be regarded as "information output means 24" which output the results of fault location. The keyboard 25 as an "input means".
Each component will be explained below.
(i) Communication interface 21 The communication interface 21 relays communication signals to and from the substations 1. Precisely, it converts signals transmitted from the substations 1 via a public data network to supply them to the central processing unit 23.
(ii) Central processing unit 23 (a personal computer, a workstation, etc.) The central processing unit 23 receives the location information and the surge detection time, which are transmitted by each substation 1, via the communication interface 21, and performs the fault point location processing, which will be described later.
Fault points obtained by processing the fault point location is output to the CRT 241 or the printer 242 together with transmission and distribution line map data stored in the auxiliary storage unit 222.
(iii) Auxiliary storage unit 222 (a hard disk, etc.) The auxiliary storage unit 222 stores the surge detection time and the location information transmitted by each substation 1, the fault points calculated by the central processing unit 23, and the transmission and distribution line map data necessary for the central processing unit 23 to perform processing.
The transmission and distribution line map data includes such data as the locations of poles and steel towers, and the distances between the poles (steel towers), etc.
(iv) Printer 242 Following the command by the central processing unit 23, the printer 242 prints out a transmission and distribution line map data or the results of fault location, which are sent by the central processing unit 23.
(v) CRT 241 Following the command of the central processing unit 23, the CRT 241 displays a transmission and distribution line map or the results of fault location, which are sent by the central processing unit 23.
(vi) Keyboard 25 (input means) The keyboard 25 is used to input drawing data, etc.
necessary for creating transmission and distribution line maps.
The drawing data outputs such data as the locations of poles and steel towers, and the distances between the poles (steel towers), etc.
(2) Processing of surge propagation speed calculation.
The calculation method for surge propagation speed processed by the surge propagation speed calculation means 23d will be explained below. When a fault occurs many possible configurations of transmission and distribution lines can be considered but they can be categorized into cases (a) and (b) below.
(a) In the case where substations are positioned on a straight line as shown in Fig. 5, substations 1A, 1B, 1C are installed in such an order on a piece of transmission and distribution line and a fault occurs at the point P between substations 1B and 1C.
When a surge is caused because of a fault, the surge propagates along the transmission and distribution line from the fault point P to and through the substations 1C, 1B, and 1A in the said order. For this reason, if the distance LõB between the substations 1A and 1B is given, the surge propagation speed võ,, between the substations 1A and 1B can be computed Formula (1) shown below.
vAB = LAU ...
tA-ta vAB : surge propagation speed between the substations 1A and 1B
L,O distance between the substations 1A and 1B
t,, : surge propagation time at the substation 1A
tg : surge propagation time at the substation 1B
(b) In the case where substations are positioned on branched lines as shown in Fig. 6, a branch-off point R is introduced on the transmission and distribution line with substations 1D, 1E, and iF positioned on each of the branched pieces of transmission and distribution line and a fault occurs at the point P between the branch-off point R and the substation 1F.
When a surge is caused because of a fault, the surge propagates along the transmission and distribution lines from the fault point P to and through the substations 1F, as well as the branch-off point R, and substations 1D and 1E. At this time, if the distance L,, between the substation 1D and the branch-off point R and the distance L,, between the substation 1E and the same are found and the two distances L,, and LR, are not equal, speed v.E of the surge propagating from the branch-off point R to both substations 1D and 1E can be computed according to Formula (2) shown below.
Further, the sections between the branch-off point R, for which the surge propagation speed vRDE is determined when the substations 1D, 1E are adjacent to the section, which includes the fault point P, between the branch-off point R and the substation 1F, and the conditions of transmission and distribution lines, as well as the weather conditions, are found to be similar. For this reason, the surge propagation speed vRDF, can be regarded as a close approximation of the surge propagation speed vRF between the branch-off point R and the substation iF.
Therefore, the surge propagation speed v.E that is obtained can be used as the surge propagation speed v which will be used for identifying the location of the fault point P.
v _ (Lnx~'LRr) (LEx~'Lxp) _LnR-L~ ...~2) RDB -tD _ tE tD _ tE
vjwE : surge propagation speed between the branch - off point R and the substations 1A and 1B
LDR : distance between the substations 1D and the branch - off point R
Lm : distance between the substations 1E and the branch - off point R
Lm : distance between the branch - off point R and the fault point P
tD : surge propagation time at the substation 1D
tE : surge propagation time at the substation 1E
By processing the calculation of surge propagation speed according to the aforesaid method for surge propagation speed to accurately determine the surge propagation speed v at the time of fault point location, errors in the location of fault points can be reduced.
(3) Processing in the fault point location system Procedures for identifying the location of a fault when one occurs on the transmission and distribution line will be explained below. First, determination of the surge detection time by a substation will be explained in the paragraphs under (a), which is followed by the explanation of fault point location by the master station in the paragraphs under (b).
(a) Determination of a surge detection time by a substation.
The procedure for determining a surge detection time by the central processing unit 141 of a substation 1 will be explained below.
A substation receives surge currents that occur at the time of a fault with the ZCT 131, detects the surge currents with the filter circuit 132 and the surge signal detection circuit 133, and outputs a surge detection signal to the surge detection time holding circuit 134. The substation, then, holds the reference time at which a surge detection signal is received in the surge detection time holding circuit 134, and outputs the reference time to the central processing unit 141 as a surge detection time, followed by the central processing unit 141 which automatically transfers the data of the detection time of the surge detection signal together with the substation number to the master station as fault information.
(b) Fault point location by the master station.
An explanation of the principle and the procedures of locating a fault point performed by the central processing unit 23 of the master station 2 will be provided below. First the principle of locating a fault point will be explained in the paragraphs under (i), and subsequently the procedures of locating a fault point will be explained in the paragraphs under (ii).
(i) Principle of locating a fault point A diagram of the principle of locating a fault point is provided in Fig. 4.
Occurrence of a ground fault within the section between substations (1) and (2) causes a travelling wave (a surge) to develop as shown in Fig. 4. The length of time required for detecting this travelling wave at substations O and is proportional to distance L1 and L2 from the point where the fault has occurred to each substation assuming that the propagation speed v of the travelling wave propagating along the transmission and distribution line is constant.
That is, if the distance L between substations (1) and and the propagation speed v of the travelling wave are known and the difference in the length of time detected at substations and is accurate, the equation "L1 = (L +(tl - t2) x v) / 2", shown in Fig. 4, allows for determination of the distance L1 from the substation (1) to the fault point.
"Propagation speed v of the travelling wave" at the time of fault point location can be determined according to the aforementioned processing of surge propagation speed calculation.
In the fault point location system of the present embodiment, the length L of a transmission and distribution line segment between substations (positioned at the source side and the end of the transmission and distribution line) which examine surge detection time differences is determined by calculation and stored in memory beforehand. This length L may be either manually input or determined by a means such as automated measurement utilizing GPS.
In addition, under the assumption that the transmission distribution line segment between substations adjacent to each other is almost straight, the positional information of both substations (longitude, latitude, and altitude) can be used to calculate the length of the transmission and distribution line segment between the two substations.
For the length of the transmission and distribution line across substations not adjacent to each other, adding each line segment between any two adjacent substations that exist between the first two substations provides the target length L.
(ii) Procedure of locating a fault point The central processing unit 23 of the master station 2, in advance, calculates and stores in memory the length L of transmission and distribution line between the substation closest to the source-side end and each substations positioned at each end of the transmission and distribution network.
Then the central processing unit 23 selects a combination of the substation 1 closest to the source-side end of the transmission and distribution line and another substation 1 closest to the ends of the trunk line and the spur lines to locate a fault point based on the difference in surge detection times at both substations.
That is, the central processing unit 23 uses a surge detection time tl at a substation on the source side, a surge detection time t2 at a substation positioned at the far end of the transmission and distribution line, surge propagation speed v, and the length L of the transmission and distribution line between the two substations to obtain the distance L1 from the substation on to the source side to the location where a fault occurred along the transmission and distribution line according to the equation L1 = (L +(tl - t2) x v) / 2.
Then, if further substations 1 are found near and across the located fault point, the reliability of the fault point location can be increased by locating the fault point again based on the difference of surge detection times at these substations.
Such a procedure of locating a fault point may be executed by an operator manually inputting necessary information for the central processing unit 23 every time a fault point location is performed or a software program may be created so that the central processing units 23 automatically handles the processing.
In this procedure, an accurate time difference will not be obtained unless the reference time at the substation on each side has been synchronized with each other, wherein, as described above, time at each substation is synchronized to correct at any time by synchronizing the reference time at each substation with the reference time sent from a GPS satellite.
(iii) Displaying a fault location The central processing unit 23 of the master station 2, after identifying a fault point location, displays transmission and distribution line map information which is stored in the auxiliary storage unit 222 and the located fault point on the screen of the CRT 241 in order to notify the operator of the location of fault occurrence. Additionally, it causes the printer 242 to print out such information according to the operators command.
(4) Operating the fault point location system Substations 1 will be mounted on poles (steel towers) supporting transmission and distribution lines and operated continuously 24 hours a day so that a fault can be detected at any time.
Master station 2 may be installed, for example, at a service office or branch office of a power company and operated only while an operator is available or 24 hours a day to quickly identify a fault point whenever a fault occurs.
(5) Effects of the fault point location system The fault point location system of the present embodiment, having a combination of the time measuring means 12 and the GPS
receiving means 11 within a substation to synchronize the substations with one another and maintain accurate time, the location of a fault point (distance from a substation to the fault point) is identified on the basis of a time difference of surge signals reaching substations positioned on both sides of a fault point (on the source side and the end of the transmission and distribution line). Additionally, the surge propagation speed is determined based on time differences between surge signals reaching each of the substations, and such surge propagation speed is used to identify the location of a fault point, therefore enabling accurate fault point location under varying conditions such as of the transmission and distribution line or weather.
[Others]
In the present invention, without being limited to the aforementioned preferred embodiment, various types of embodiments are possible according to the purpose, use, etc. That is, in the present embodiment, substations used for obtaining surge propagation speeds are those positioned adjacent to a fault point, however speed values can be calculated using a substation separated by several other substations. Likely, a pair of substations used for calculation does not need to be those adjacent to each other but rather other substations can be positioned between them. By extending the distance between substations, as illustrated here, time differences of surges reaching the substations increase, which makes determination of surge propagation speed easier.
Public networks such as the cellular phone system, PHS
(Personal Handy-phone System), or public telephone network can be used for the transfer of information from the substations to the master station, or a dedicated network (of metal cables, optical fibers, radio waves, etc.) installed along transmission and distribution lines can also be used. Additionally, modulated signals can be propagated through the transmission and distribution lines.
Furthermore, embodiments of the storage means of the map data of the transmission and distribution line map information are not limited to using an auxiliary storage unit and storage is possible on other recording media such as magnetic disks, optical disks (CD-ROM, DVD, etc.), magneto-optical disks. Likewise, it can be so arranged that map data is downloaded from a WWW site which manages a map information system on the Internet and is retrieved on-line. It will be possible to obtain the most up-to-date map information if data is downloaded from the server via the Internet or retrieved on-line, in which case maintaining ones own map information will no longer be necessary.
receiving means 11 within a substation to synchronize the substations with one another and maintain accurate time, the location of a fault point (distance from a substation to the fault point) is identified on the basis of a time difference of surge signals reaching substations positioned on both sides of a fault point (on the source side and the end of the transmission and distribution line). Additionally, the surge propagation speed is determined based on time differences between surge signals reaching each of the substations, and such surge propagation speed is used to identify the location of a fault point, therefore enabling accurate fault point location under varying conditions such as of the transmission and distribution line or weather.
[Others]
In the present invention, without being limited to the aforementioned preferred embodiment, various types of embodiments are possible according to the purpose, use, etc. That is, in the present embodiment, substations used for obtaining surge propagation speeds are those positioned adjacent to a fault point, however speed values can be calculated using a substation separated by several other substations. Likely, a pair of substations used for calculation does not need to be those adjacent to each other but rather other substations can be positioned between them. By extending the distance between substations, as illustrated here, time differences of surges reaching the substations increase, which makes determination of surge propagation speed easier.
Public networks such as the cellular phone system, PHS
(Personal Handy-phone System), or public telephone network can be used for the transfer of information from the substations to the master station, or a dedicated network (of metal cables, optical fibers, radio waves, etc.) installed along transmission and distribution lines can also be used. Additionally, modulated signals can be propagated through the transmission and distribution lines.
Furthermore, embodiments of the storage means of the map data of the transmission and distribution line map information are not limited to using an auxiliary storage unit and storage is possible on other recording media such as magnetic disks, optical disks (CD-ROM, DVD, etc.), magneto-optical disks. Likewise, it can be so arranged that map data is downloaded from a WWW site which manages a map information system on the Internet and is retrieved on-line. It will be possible to obtain the most up-to-date map information if data is downloaded from the server via the Internet or retrieved on-line, in which case maintaining ones own map information will no longer be necessary.
Claims (2)
1. A fault point location system comprising:
substations installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station; and the master station for locating a fault point on the a basis of the surge detection time information; wherein each of the substations, that function as a clock, are capable of receiving radio waves from a GPS
satellite and identifying the time held by the GPS satellite to synchronize its own time with the time held by the GPS satellite, detecting surge currents or surge voltages occurring along the transmission and distribution lines, determining a surge detection time at which the surge currents or surge voltages are detected, and transferring the surge detection time to the master station through a communication network;
wherein, when the master station receives the surge detection time from any of the substations via the communication network, the master station identifies a location where a fault has occurred on the transmission and distribution lines based on a difference of the surge detection times from two of the substations positioned at each end of a fault section, a length of the transmission and distribution line of the fault section, and the surge propagation speed; and the surge propagation speed V is obtained on a basis of a surge detection time t A at a first substation positioned adjacent to a fault point along the transmission and distribution lines, a surge propagation time t B at another substation positioned next to the first substation, a distance L AB between the first substation and the another substation, according to the equation and whereby the master station uses a surge detection time t1 at a substation closest to a source-side end of the transmission and distribution line, a surge detection time t2 at a substation positioned at a far end of the transmission and distribution line, the surge propagation speed V, and the length L of the transmission and distribution line between the substation closest to the source-side end of the transmission and distribution line and the substation positioned at the far end of the transmission and distribution line to obtain a distance L1 from the substation closest to the source-side end to the fault point along the transmission and distribution line according to the equation L1 = (L
+(t1 - t2) x v)/2; and wherein the master station further uses a surge detection time t3 at a first of a pair of substations situated across the fault point found as per the calculation above, a surge detection time t4 at a second of the pair of substations, the surge propagation speed v, and the length L' of the transmission and distribution line between the pair of substations to obtain a distance L3 from the first of the pair of substations to the fault point along the transmission and distribution line according to the equation L3 = (L' + (t3 - t4) x v)/2.
substations installed along transmission and distribution lines for sending surge detection time information along the transmission and distribution lines to a master station; and the master station for locating a fault point on the a basis of the surge detection time information; wherein each of the substations, that function as a clock, are capable of receiving radio waves from a GPS
satellite and identifying the time held by the GPS satellite to synchronize its own time with the time held by the GPS satellite, detecting surge currents or surge voltages occurring along the transmission and distribution lines, determining a surge detection time at which the surge currents or surge voltages are detected, and transferring the surge detection time to the master station through a communication network;
wherein, when the master station receives the surge detection time from any of the substations via the communication network, the master station identifies a location where a fault has occurred on the transmission and distribution lines based on a difference of the surge detection times from two of the substations positioned at each end of a fault section, a length of the transmission and distribution line of the fault section, and the surge propagation speed; and the surge propagation speed V is obtained on a basis of a surge detection time t A at a first substation positioned adjacent to a fault point along the transmission and distribution lines, a surge propagation time t B at another substation positioned next to the first substation, a distance L AB between the first substation and the another substation, according to the equation and whereby the master station uses a surge detection time t1 at a substation closest to a source-side end of the transmission and distribution line, a surge detection time t2 at a substation positioned at a far end of the transmission and distribution line, the surge propagation speed V, and the length L of the transmission and distribution line between the substation closest to the source-side end of the transmission and distribution line and the substation positioned at the far end of the transmission and distribution line to obtain a distance L1 from the substation closest to the source-side end to the fault point along the transmission and distribution line according to the equation L1 = (L
+(t1 - t2) x v)/2; and wherein the master station further uses a surge detection time t3 at a first of a pair of substations situated across the fault point found as per the calculation above, a surge detection time t4 at a second of the pair of substations, the surge propagation speed v, and the length L' of the transmission and distribution line between the pair of substations to obtain a distance L3 from the first of the pair of substations to the fault point along the transmission and distribution line according to the equation L3 = (L' + (t3 - t4) x v)/2.
2. A fault point location system as described in claim 1, wherein the master station uses:
(a) the surge detection time t1 at the first of the pair of substations situated across the fault point along the transmission and distribution line;
(b) the surge detection time t2 at the second of the pair of substations; and (c) the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the first substation to the fault point along the transmission and distribution line according to the equation L1 = (L +(t1 -t2) x v)/2.
(a) the surge detection time t1 at the first of the pair of substations situated across the fault point along the transmission and distribution line;
(b) the surge detection time t2 at the second of the pair of substations; and (c) the surge propagation speed v, and the length L of the transmission and distribution line between the pair of substations to obtain the distance L1 from the first substation to the fault point along the transmission and distribution line according to the equation L1 = (L +(t1 -t2) x v)/2.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31358099A JP4564615B2 (en) | 1999-11-04 | 1999-11-04 | Fault location system |
| JP313580/1999 | 1999-11-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2325101A1 CA2325101A1 (en) | 2001-05-04 |
| CA2325101C true CA2325101C (en) | 2010-02-02 |
Family
ID=18043031
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002325101A Expired - Lifetime CA2325101C (en) | 1999-11-04 | 2000-11-03 | Method of calculating surge propagation speed and system for locating fault points by the use thereof |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4564615B2 (en) |
| CA (1) | CA2325101C (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5085111B2 (en) * | 2006-12-01 | 2012-11-28 | 九州電力株式会社 | Calculation method of surge propagation speed in accident location system |
| WO2015080569A1 (en) * | 2013-11-28 | 2015-06-04 | Lee Soon Tan | An automatic power fault detection method and system for monitoring and controlling a power distribution system |
| JP6263034B2 (en) * | 2014-01-24 | 2018-01-17 | 九電テクノシステムズ株式会社 | Fault location system and fault location method |
| JP6449663B2 (en) * | 2015-02-03 | 2019-01-09 | 中国電力株式会社 | Fault location method and fault location system |
| BR112020018356A2 (en) * | 2018-03-16 | 2020-12-29 | Siemens Aktiengesellschaft | METHOD AND DEVICE TO LOCATE FAILURE POINT IN AREA NETWORK BASED ON PROGRESSIVE WAVE, AND STORAGE MEDIA |
| WO2020059066A1 (en) * | 2018-09-20 | 2020-03-26 | 中国電力株式会社 | Ground fault point locating device, ground fault point locating system, ground fault point locating method, program, and recording medium |
| JP7378725B2 (en) | 2019-10-16 | 2023-11-14 | 中国電力株式会社 | Measurement terminal, measurement terminal setting method, ground fault location system |
| JP7360663B2 (en) | 2019-10-17 | 2023-10-13 | 西日本電線株式会社 | Abnormal location identification device, system and program |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2599613B2 (en) * | 1988-03-24 | 1997-04-09 | 東北電力 株式会社 | Transmission line fault location system using artificial satellites |
| JPH0454470A (en) * | 1990-06-25 | 1992-02-21 | Sumitomo Electric Ind Ltd | Fault point locating device for power transmission line |
-
1999
- 1999-11-04 JP JP31358099A patent/JP4564615B2/en not_active Expired - Lifetime
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2000
- 2000-11-03 CA CA002325101A patent/CA2325101C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2325101A1 (en) | 2001-05-04 |
| JP2001133504A (en) | 2001-05-18 |
| JP4564615B2 (en) | 2010-10-20 |
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