Fault point location system

• US 6,477,475 B1
• Filed: 11/09/1999
• Issued: 11/05/2002
• Est. Priority Date: 11/12/1998
• Status: Expired due to Term

• Current Assignee: Motokuni Takaoka, Nippon Kouatsu Electric Co., Ltd.
• Original Assignee: Motokuni Takaoka, Nippon Kouatsu Electric Co., Ltd.
• Inventors: Sugiura, Masanori, Takaoka, Motokuni
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Charioui, Mohamed
• Application Number:
  US09/436,237
• Time in Patent Office: 1,092 Days
• Field of Search: 702/57, 702/58, 702/59, 714/25, 701/213, 701/214, 701/215, 324/535, 455/503, 455/67.3
• US Class Current: 702/59
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks

Abstract

A fault point location system comprising substations 1 to send information of transmission and distribution lines, and the master station 2 to locate fault points under the information. Substation 1 detects a surge detection time and the surge current polarity. Master 2 identifies a no-branch fault section under the polarity, and identifies the fault point under a difference among detection times of substations 1 at both ends of the section, and the section length.

Claims

1. A fault point location system comprising:

substations 1 installed along transmission and distribution lines for sending information along said transmission and distribution lines to a master station 2, and the master station 2 for locating fault points on the basis of the information sent by said substations 1;

wherein said substation 1 has a clock function, receives radio waves from a GPS satellite to identify the current time the GPS has, is able to synchronize the current time said GPS has with the self current time, detects a surge current or surge voltage of the transmission and distribution line along which said substation 1 is installed to identify a surge detection time, the time at which said surge current or surge voltage is detected, recognizes the polarity of said surge current, and then sends said surge detection time and information on said polarity to said master station 2 via a communication network; and

said master station 2 receives said surge detection time and information on said polarity, which are transmitted from said substation 1 via the communication network, identifies a section with no branch as the section of occurrence of a fault on the basis of information on said polarity of each substation 1, and identifies the point of occurrence of a fault along the transmission and distribution line on the basis of a difference in the time of detection of said surge detected by substations 1 at both ends of said fault section, and the length of said fault section along the transmission and distribution line,

wherein said substation 1 comprises a GPS receiving means 11, a time measuring means 12, a surge detection means 13, and a surge information transmitting means 14b, wherein

said GPS receiving means 11 receives GPS radio waves from satellites for identifying the current time the GPS has to send the current time said GPS has to said time measuring means 12,

said time measuring means 12 has a clock function for synchronizing the current time said GPS has from said GPS receiving means 11 with the current time of said substation 1 and then sends information on said current time of said substation 1 to the surge detection means 13,

said surge detection means 13 detects a surge current or surge voltage of a transmission and distribution line along which said substation 1 is installed, identifies the time of surge detection time at which said surge detection signal is received on the basis of information on the time sent by said time measuring means 12, also recognizes a polarity of said surge current, and transmits said surge detection time and said polarity to said surge information transmitting means 14b, and

said surge information transmitting means 14b sends said surge detection time and said information on polarity to said master station 2 via a communication network; and

said master station 2 comprising a substation surge information receiving means 21b, a fault section identifying means 23b, and a fault location identifying means 23c, wherein

said substation surge information receiving means 21b receives said surge detection time sent by said surge information transmitting means 14b and said information on polarity via a communication network, then sends said information on polarity to said fault section identifying means 23b, and sends said surge detection time to fault location identifying means 23c,

said fault section identifying means 23b identifies a section with no branch as a section of occurrence of a fault on the basis of said information on polarity of each substation 1 and sends said section as a fault section to said fault location identifying means 23c, and

said fault location identifying means 23c identifies a point of occurrence of a fault along a transmission and distribution line on the basis of a difference in said surge detection time of substations 1 at both ends of said fault section and the length of the transmission and distribution line of said fault section,

wherein, in accordance with said surge detection time t1 detected at one of the substations at both ends of said fault section, said surge detection time t2 of the other substation, surge propagation velocity v, and length L of the transmission and distribution line of the section of said fault has occurred, said fault location identifying means determines distance L1 on a transmission and distribution line from one of the substations to the location of the fault along the transmission and distribution line is determined by equation L1=(L+(t1−

t2)×

v)/2,

said fault location identifying means to identify sections of occurrence of a fault through the procedures wherein;

(1) Select one transmission and distribution line that extends from a power source,

(2) Compare data of a surge rising polarity of a substation with that of its neighboring substation along said transmission and distribution line selected,

(3) If there is a substation of a polarity opposite to its neighboring substation and the section with said substations located at the ends of the section has no branch, decide that the section is “

the section with a fault”

,

(4) If there is a substation of a polarity opposite to its neighboring substation and the section with said substations located at the ends of the section has a branch, compare the surge rising polarity data of the most upstream substation among the substations of the spur transmission and distribution line with the surge rising polarity data of the upstream substation among substations which have a polarity opposite to their neighboring substation of the trunk transmission and distribution line,

(5) If the polarity of the most upstream substation among the substations of said spur transmission and distribution line is opposite to the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, decide that the section ranging from the most upstream substation among the substations of said spur transmission and distribution line through the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line to the downstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line is a “

section of a fault”

,

(6) If the polarity of the most upstream substation among the substations of said spur transmission and distribution line is the same as the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, select one transmission and distribution line out of said spur transmission and distribution lines to replace said “

one transmission and distribution line selected”

with the transmission and distribution line out of said spur transmission and distribution lines and perform the procedures from the foregoing 2.

2. A fault point location system comprising;

substations 1 which are installed along a transmission and distribution line to transmit information on said transmission and distribution line to a master station 1, and

a master station 2 which prepares information along transmission and distribution lines on the basis of information from said substations 1 to locate faults;

said fault point location system characterized in that

said substation 1 receives GPS radio waves from a satellite for identifying its own position on the basis of said GPS radio waves and then transmits information on said own position to said master station 2 via communication networks,

further, said master station 2 receives the information on the position of said substation 1 sent by said substation 1 via communication networks for preparing transmission and distribution line map information which has transmission and distribution lines illustrated on a map on the basis of map information on a region where each substation is installed and information on the position of said substations, and then outputs said transmission and distribution line map information,

said substation 1 has a clock function, receives radio waves from a GPS satellite to identify the current time of the GPS, is able to synchronize the current time of said GPS with the self current time, detects a surge current or surge voltage of the transmission and distribution line along which said substation 1 is installed to identify a surge detection time, the time at which said surge current or surge voltage is detected, recognizes the polarity of said surge current, and then sends said surge detection time and information on said polarity to said master station 2 via a communication network, and

said master station 2 receives said surge detection time and information on said polarity, which are transmitted from said substation 1 via the communication network,

identifies a section with no branch as the section of an occurrence of a fault on the basis of information on said polarity of each substation 1,

identifies the point of an occurrence of a fault along the transmission and distribution line on the basis of a difference in the time of detection of said surge detected by substations 1 at both ends of said fault section, and the length of said fault section along the transmission and distribution line,

identifies said point of occurrence of a fault along the transmission and distribution line on a transmission and distribution line of said transmission and distribution line map information,

re-prepares the transmission and distribution line map information in consideration of said identified information at the point of occurrence of a fault, and

outputs said re-prepared transmission and distribution line map information.

3. A fault point location system according to claims 2, wherein,

said substation 1 comprises a GPS receiving means 11, a time measuring means 12, a surge detection means 13, a self-position information transmitting means 14a, and a surge information transmitting means 14b;

said master station 2 comprises a substation location information receiving means 21a, a substation surge information receiving means 21b, a map information storage means 22, a transmission and distribution line map information preparing means 23a, a fault section identifying means 23b, a fault location identifying means 23c, and a transmission and distribution line map information output means 24;

said GPS receiving means 11 receives GPS radio waves from a satellite for identifying its own position on the basis of said GPS radio waves and then transmits information on said own position to said self-position information transmitting means 14a;

said self-position information transmitting means 14a transmits information on said own position to said master station 2 via communication networks;

said substation location information receiving means 21a receives the information on the position of said substation 1 sent by said self-position information transmitting means 14a via communication networks to transmit the information on the position of said substation 1 to said transmission and distribution line map information preparing means 23a;

said map information storage means 22 is able to provide map information on a region where each substation is installed for said transmission and distribution line map information preparing means 23a;

said transmission and distribution line map information preparing means 23a receives said map information from said map information storage means 22 for preparing transmission and distribution line map information which has transmission and distribution lines illustrated on a map on the basis of said map information and the information on the position of said substations which was received from said substation location information receiving means 21a to transmit said transmission and distribution line map information to said transmission and distribution line map information output means 24;

said transmission and distribution line map information output means 24 outputs said transmission and distribution line map information;

further, said GPS receiving means 11 receives GPS radio waves from a satellite to identify the current time of the GPS and transmits said current time of the GPS to said time measuring means 12;

said time measuring means 12 has a clock function, is able to synchronize the current time said GPS has sent by said GPS receiving means 11 with the self current time, and transmits said self current time information to the surge detection means 13;

said surge detection means 13 detects a surge current or surge voltage of the transmission and distribution line along which said substation 1 is installed to identify a surge detection time, the time at which said surge current or surge voltage signal is received, on the basis of information on the time from said time measuring means 12, recognizes the polarity of said surge current, and then sends said surge detection time and information on said polarity to said surge information transmitting means 14b;

said surge information transmitting means 14b sends said surge detection time and information on said polarity to said master station 2 via a communication network;

said substation surge information receiving means 21b receives said surge detection time and said information on polarity, which are transmitted from said surge information transmitting means 14b, via the communication network, transmits said information on polarity to said fault section identifying means 23b, and transmits said surge detection time to said fault location identifying means 23c;

said fault section identifying means 23b identifies a section with no branch as the section of an occurrence of a fault on the basis of information on said polarity of each substation 1 and transmits said section as a fault section to said fault location identifying means 23c;

said fault location identifying means 23c identifies the point of occurrence of a fault along the transmission and distribution line on the basis of a difference in the time of detection of said surge detected by substations 1 at both ends of said fault section, and the length of said fault section along the transmission and distribution line;

said transmission and distribution line map information preparing means 23a identifies said point of occurrence of a fault along the transmission and distribution line on a transmission and distribution line of said transmission and distribution line map information, re-prepares the transmission and distribution line map information in consideration of said identified information at the point of occurrence of a fault as well, and transmits said re-prepared transmission and distribution line map information to said transmission and distribution line map information output means 24; and

said transmission and distribution line map information output means 24 outputs said re-prepared transmission and distribution line map information.

4. A fault point location system according to claims 3, wherein, in accordance with said surge detection time t1 detected at one of the substations at both ends of said fault section, said surge detection time t2 of the other substation, surge propagation velocity v, and length L of the transmission and distribution line of the section of said fault has occurred, said fault location identifying means determines distance L1 on a transmission and distribution line from one of the substations to the location of the fault along the transmission and distribution line is determined by equation L1=(L+(t1−

t2)×

v)/2.

5. A fault point location system according to claims 4, said fault location identifying means to identify sections of occurrence of a fault through the procedures wherein:

(1) Select one transmission and distribution line that extends from a power source,

(2) Compare data of a surge rising polarity of a substation with that of its neighboring substation along said transmission and distribution line selected,

(3) If there is a substation of a polarity opposite to its neighboring substation and the section with said substations located at the ends of the section has no branch, decide that the section is “

the section with a fault”

,

(4) If there is a substation of a polarity opposite to its neighboring substation and the section with said substations located at the ends of the section has a branch, compare the surge rising polarity data of the most upstream substation among the substations of the spur transmission and distribution line with the surge rising polarity data of the upstream substation among substations which have a polarity opposite to their neighboring substation of the trunk transmission and distribution line,

(5) If the polarity of the most upstream substation among the substations of said spur transmission and distribution line is opposite to the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, decide that the section ranging from the most upstream substation among the substations of said spur transmission and distribution line through the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line to the downstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line is a “

section of a fault”

,

(6) If the polarity of the most upstream substation among the substations of said spur transmission and distribution line is the same as the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, select one transmission and distribution line out of said spur transmission and distribution lines to replace said “

one transmission and distribution line selected”

with the transmission and distribution line out of said spur transmission and distribution lines and perform the procedures from the foregoing 2.

6. A fault point location system according to any one of claims 4 or 5, wherein said surge propagation velocity is 150 to 300 m/μ

s.

7. A fault point location system comprising:

substations 1 installed along transmission and distribution lines for sending information on said transmission and distribution lines to a master station 2, and

the master station 2 for locating fault points on the basis of the information sent by said substations 1;

wherein said substation 1 has a clock function, receives radio waves from a GPS satellite to identify the current time of the GPS, is able to synchronize the current time of said GPS with the self current time, detects a surge current or surge voltage of the transmission and distribution line on which said substation 1 is installed to identify a surge detection time, the time at which said surge current or surge voltage is detected, recognizes the polarity of said surge current, and then sends said surge detection time and information on said polarity to said master station 2 via a communication network; and

said master station 2 receives said surge detection time and information on said polarity, which are transmitted from said substation 1 via the communication network, identifies a potential point of an occurrence of a fault along the transmission and distribution line on the basis of a difference in said surge detection time between said substation 1 which is the nearest to the source-side of said transmission and distribution line and a plurality of distal substations 1 of said transmission and distribution line, and the length of the transmission and distribution line between said substations 1 and 1, and totally identifies a predetermined range of a transmission and distribution line with said potential point as a fault point potential section, and identifies a section with no branch as a section of an occurrence of a fault to determine a fault section on the basis of the information on polarities of a substation 1 within said fault point potential section and a substation, which is not included in said fault point potential section, adjacent to the substation 1 which is included in said fault point potential section,

wherein said substation 1 comprises a GPS receiving means 11, a time measuring means 12, a surge detection means 13, and a surge information transmitting means 14b, wherein

said GPS receiving means 11 receives GPS radio waves from satellites for identifying the current time of the GPS and sends the current time of said GPS to said time measuring means 12,

said time measuring means 12 has a clock function for synchronizing the current time of said GPS from said GPS receiving means 11 with the current time of said substation 1 and then sends information on said current time of said substation 1 to the surge detection means 13,

said surge detection means 13 detects a surge current or surge voltage of a transmission and distribution line along which said substation 1 is installed, identifies the time of surge detection time at which said surge detection signal is received on the basis of information on the time sent by said time measuring means 12, also recognizes a polarity of said surge current, and transmits said surge detection time and said polarity to said surge information transmitting means 14b, and

said surge information transmitting means 14b sends said surge detection time and said information on polarity to said master station 2 via a communication network; and

said master station 2 comprises a substation surge information receiving means 21b, a fault point potential identifying means 23e, and a fault range confining means 23d, wherein

said substation surge information receiving means 21b receives said surge detection time sent by said surge information transmitting means 14b and said information on polarity via a communication network, then sends said surge detection time to said fault point potential identifying means 23e, and sends said information on polarity to said fault range confining means 23d,

said fault point potential identifying means 23e identifies a potential point of occurrence of a fault along the transmission and distribution line on the basis of a difference in said surge detection time between said substation 1 which is the nearest to the source-side end of said transmission and distribution line and a plurality of distal substations 1 of said transmission and distribution line, and the length of the transmission and distribution line between said substations 1 and 1, and totally identifies a predetermined range of a transmission and distribution line with said potential point as a fault point potential section to be transmitted to said fault range confining means 23d,

said fault range confining means 23d identifies a section with no branch as a section of an occurrence of a fault to determine a fault section on the basis of the information on polarities of a substation 1 within said fault point potential section and a substation, which is not included in said fault point potential section, adjacent to the substation 1 which is included in said fault point potential section,

wherein said fault range confining means;

(1) selects one predetermined transmission and distribution line from a group of transmission and distribution lines among substations included within said fault location potential sections and substations that are not included within said fault location potential sections but adjacent to substations included within said fault location potential sections and are added to said fault location potential sections into a group of transmission and distribution lines;

(2) compares data of a surge rising polarity of a substation with that of its neighboring substation on said transmission and distribution line selected;

(3) selects one predetermined transmission and distribution line from a group of transmission and distribution lines among substations included within said fault location potential sections and substations that are not included within said fault location potential sections but adjacent to substations included within said fault location potential sections and are added to said fault location potential sections into a group of transmission and distribution lines if there is no substation of a polarity opposite to the neighboring substation thereof to be replaced for said “

one transmission and distribution line selected” and

then performs from the procedure 2, and decides that there is no fault point if there is no transmission and distribution line along which a fault section has not been checked;

(4) if there is a substation of a polarity opposite to that of its neighboring substation and the section with these substations located at the ends of the section has no branch, identifies the section as a fault section;

(5) if there is a substation of a polarity opposite to that of its neighboring substation and the section with these substations located at the ends of the section has a branch, compares the surge rising polarity data of the most upstream substation among the substations of the spur transmission and distribution line with the surge rising polarity data of the upstream substation among substations which have a polarity opposite to that of their neighboring substation of the trunk transmission and distribution line;

(6) if there the polarity of the most upstream substation among the substations of said spur transmission and distribution line is opposite to the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, determines, to be a fault section, the section from the most upstream substation among the substations of said spur transmission and distribution line through the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line to the downstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line; and

(7) if there the polarity of the most upstream substation among the substations of said spur transmission and distribution line is the same as the polarity of the upstream substation among substations which have a polarity opposite to their neighboring substation of said trunk transmission and distribution line, selects one transmission and distribution line from said spur transmission and distribution lines to be replaced for said “

one transmission and distribution line selected” and

then performs the procedures from the foregoing procedure 2.