JP2015038445A - Power transmission line fall point orientation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately locate a surge occurrence point having various magnitudes due to causes such as a lightning stroke, contact with a bird or a beast, and contact with a tree.SOLUTION: A plurality of key stations and slave stations are arranged on a power transmission line. Plural surge arrival point detection means 15 of the slave station detects a surge arrival point T1 close to a rising of a surge waveform and a surge arrival point T2 in which the influence of noise immediately before the generation of the surge is small. Fault information transmission means 16 transmits, to the key station, the time of the surge arrival points T1, T2, fault current information from fault current detection means 12 and fault voltage information from fault voltage detection means 13 as fault information. The key station selects slave stations used for orientation based on the fault information, and calculates a surge occurrence point from a time difference of the surge arrival points T1, T2 respectively at these slave stations so as to be displayed with a priority order given according to predetermined conditions. Further, a fault occurrence and a surge other than the fault occurrence are distinguished and displayed by a fault state flag from current voltage monitoring means 14.

Description

  The present invention relates to a transmission line failure point locating system, and more particularly to a transmission line failure point locating system for locating a failure point based on a surge generated in a transmission line.

  Conventionally, surges that occur when the transmission line is grounded, short-circuited, or when lightning strikes the transmission line directly are received by the master station and slave stations provided at the transmission and reception ends of the transmission line, generating a surge. There is known a surge locating system for locating locations.

  FIG. 8 is a diagram illustrating the principle of a conventional surge orientation system. In this fault location system, the surge arrival time is detected at the master station 2 (electricity station A) and the slave station 3 (electricity station B) provided at the end of the transmission line 1, and the difference between the detected surge arrival times is obtained. The distance L1 from the master station 2 to the surge occurrence location is calculated using the following equation (1).

  L1 = (L + c · Δt) / 2 (1)

  Where L is the distance between the master station 2 and the slave station 3 installed at both ends of the transmission line 1, Δt is the difference in surge arrival time between the master station 2 and the slave station 3, and c is the surge propagation Is speed.

  The waveform shape, wavefront length, peak value, etc. of the surge reaching the slave station at the receiving end of the transmission line fluctuate or attenuate depending on the length of the transmission line, the presence or absence of branching, the cause of the surge, the characteristics of the sensor that takes in the surge, and the like. In view of this, the present inventors have proposed a transmission line fault location system that can determine fault points relatively easily and accurately even in such a case.

  FIG. 9 is an explanatory diagram of the principle of this power transmission line fault location system. In this transmission line fault location system, fault current information and fault voltage information are detected by a plurality of slave stations 43 to 50 arranged on the transmission line, and the master station 42 detects fault current detected by the slave stations 43 to 50. Group them according to the information or fault voltage information, select the slave station that detected the earliest surge in each group as the optimum slave station for fault location, and use the time difference of the surge detection time of the selected slave station Locate the point of failure. In the example of FIG. 9, the grouping is performed by a group of slave stations 43 and 44 having a current value of 200A and a phase of 0 °, a group of slave stations 45 to 47 having a current value of 200A and a phase of 180 °, and a slave station of a current value of 0A. 50 groups.

  Patent Document 2 describes a failure point locating system that accurately estimates a rising point of a surge waveform and locates a failure point even if the noise level fluctuates or the surge waveform rises slowly. . In this failure point locating system, as shown in FIG. 10, a surge waveform is recorded when a surge waveform change satisfies a preset activation condition, and a moving average process is performed on the recorded surge waveform. And filtering by differential data absolute value processing to take measures against noise, and for the surge waveform after noise suppression, the local maximum point closest to the starting point after the starting point (surge waveform with differential data absolute value processing applied) (The point where the waveform is undulating becomes the maximum value) is detected as the peak point P1 of the surge waveform, and the point P2 below the maximum noise level before the start point is detected going back from the peak point P1 to the waveform To do. Then, a zero cross point of a straight line passing through the peak points P1 and P2 is defined as a surge waveform rising point, and the time at the rising point is defined as a surge waveform arrival time.

JP 2005-121434 A JP 2011-196819 A

  The transmission line has a long line length and often has a branch in the middle. When a lightning strike or the like propagates through the transmission line, the high-frequency line segment is demultiplexed by the branch and the level is lowered. For this reason, in the conventional surge localization system of FIG. 8, it is necessary to lower the detection threshold value so that the surge can be reliably detected at both ends of the line. However, if the detection threshold is lowered, there is a problem that an induced lightning surge or noise immediately before the occurrence of a surge is frequently detected.

  In addition, surge occurs due to various factors such as lightning strike, bird contact, and tree contact, and the generated surge waveform varies depending on the factor. In particular, the current flowing through the transmission line due to a lightning strike (lightning current) is large, and the surge voltage is also large. For example, if the ground resistance of the steel tower of the transmission voltage 66kV transmission line is 10Ω and the average lightning current in the case of lightning strike is 30KA, a surge voltage of 300kV is generated by lightning strike when the lightning strikes on the steel tower. On the other hand, in the case of contact with birds and beasts, only a surge voltage of about 80% of the transmission voltage 66 kV is generated, and the surge voltage is about 1/5 or less than that of a lightning strike. Lightning strikes are a natural phenomenon, and even if noise countermeasures are taken by filtering, if a lightning strike that exceeds the filtering performance occurs, the noise becomes large and the failure point cannot be accurately determined.

  In the transmission line fault location system of Patent Document 1, since the slave station closest to the failure point is selected, this is an effective measure for attenuation or reduction in the level of surge propagating through the transmission line. If this occurs, the error in fault location becomes large.

  In the fault location system of Patent Document 2, the rising point of the surge waveform is obtained from the maximum noise level and surge waveform peak point based on the starting point when the change of the surge waveform satisfies a preset starting condition, and this rising point is obtained. Since the point time is the surge arrival time, the influence of noise can be reduced and the failure point can be determined. However, as described above, the surge waveform varies depending on the cause of the occurrence of the surge, and it is difficult to set the start condition for accurately detecting all the surges. That is, if the activation condition is set to a level higher than noise to detect lightning strike surges, low level surges such as bird and animal contact surges and tree contact surges cannot be detected. If the activation condition is set to a low level to detect the occurrence of noise, noise generated with a lightning strike surge may satisfy the activation condition, and the failure point cannot be accurately determined.

  FIG. 11 shows a waveform example of a lightning strike surge and a wildlife contact surge. Here, the vertical axis is a value indicating a measure of the magnitude (level) of surge, and the horizontal axis is a time axis in msec units. As shown in FIG. 11, the peak value of the lightning strike surge is about 5000, whereas the peak value of the bird and animal contact surge is about 500, which is 1/10 of the peak value.

  In order to detect both of these surges using the technique of the fault location system of Patent Document 2 (FIG. 10), it is necessary to set the starting point to a level lower than the level of the bird and animal contact surge. For example, when the activation condition is set to the surge level 300, the arrival time of the bird and animal contact surge can be detected correctly. However, in this case, in the lightning strike surge, the arrival time is detected by using the noise before the surge as the surge, and therefore the arrival time of the surge cannot be detected correctly. For this reason, the error in locating the failure point increases, and the failure point cannot be accurately determined. In addition, when the activation condition is set to a level 1000 higher than the maximum value of noise before the occurrence of the lightning strike surge, the arrival time of the lightning strike surge can be detected correctly. However, in this case, it is impossible to detect a bird and animal contact surge.

  An object of the present invention is to provide a transmission line fault location system capable of accurately locating a fault point of various magnitude surges due to factors such as lightning strikes, bird contact, and tree contact even when there is a branch in the transmission line. It is in.

  In order to solve the above-described problem, the present invention provides a plurality of slave stations arranged on a transmission line and transmitting failure information of the transmission line to a master station, and a failure point based on the failure information transmitted from the slave station. In the failure point locating system having a master station for locating the GPS, the slave station receives GPS radio waves from an artificial satellite and detects the current that the GPS has, and a fault current flowing in the transmission line A fault current detecting means for sending fault current information, a fault voltage detecting means for detecting fault voltage generated in the transmission line and sending fault voltage information, and a fault by at least one of fault current information and fault voltage information It has current voltage monitoring means that sends out a failure state flag according to the occurrence state and surge detection means, and when the surge exceeds a preset surge detection threshold, it records the surge waveform for a predetermined period before and after that point. ,Record Among the multiple points that are values obtained by multiplying the maximum peak value by a predetermined ratio of the first to nth (n is an integer equal to or greater than 2), The point that occurred at the earliest time is determined for each ratio, and the zero cross point of the straight line passing through two points on the surge waveform in the vicinity thereof is used as the first to nth surge arrival points, and those times are obtained from the GPS receiving means. A plurality of surge arrival point detection means for detecting the first to nth surge arrival point time by taking out, the first to nth surge arrival point time, the failure current information and the failure voltage information as failure information, The failure information is configured to be transmitted to the master station in accordance with a failure status flag, or includes failure information transmission means configured to transmit the failure information including a failure status flag. The plurality of slave stations Failure information receiving means for receiving failure information transmitted from the failure information and selecting a slave station to be used for orientation based on the failure information, and first to n-th surges in the slave stations selected by the failure information receiving means Surge occurrence point multiple calculation processing means for calculating the first to nth surge occurrence points according to the time difference of each arrival point time, and the failure information is transmitted from the failure information transmission means according to the failure flag. The first to n-th surge occurrence points are displayed as failure points, and failure information including a failure state flag is transmitted from the failure information transmission means. If there is a failure, a priority is given according to a predetermined condition, and the first to nth surge occurrence points are displayed by distinguishing between the occurrence of a failure and other surges according to the failure status flag. The first feature is that a position processing means is provided.

  Further, the present invention, the surge occurrence point priority processing means, a predetermined condition whether or not the magnitude of the surge maximum peak value is larger than a preset (n-1) first priority determination value As a second feature, priority is given to the first to nth surge occurrence points.

  The present invention has a third feature in that at least one of the first priority order determination value and the priority order is variable.

  Further, the present invention, the surge occurrence point priority processing means, whether or not the magnitude of the crest value of the fault current or fault voltage is greater than a preset (n-1) second priority determination value As a predetermined condition, the fourth feature is that priorities are assigned to the first to nth surge occurrence points.

  The fifth feature of the present invention is that at least one of the second priority order determination value and the priority order is variable.

  Further, according to the present invention, when the surge occurrence point priority order processing means has an absolute value of a distance difference of at least two of the first to nth surge occurrence points exceeding a predetermined value, the first to first When priority is given to n surge occurrence points and the absolute value of the distance difference between the 1st to nth surge occurrence points is less than or equal to a predetermined value, only the surge occurrence point with the highest priority or the first A sixth feature is that the average point of the 1st to nth surge occurrence points is displayed.

  In the present invention, a plurality of surges are reached using a plurality of threshold values obtained by multiplying the maximum peak value of the surge by a predetermined plurality of ratios, that is, using a plurality of threshold values having relative values to the magnitude of the surge. Since the point is detected, even if a surge having a different magnitude occurs due to various factors such as lightning strike, contact with birds and animals, and tree contact, the arrival point can be detected with high accuracy.

  In addition, multiple surge arrival points are detected from points close to the rise of the surge waveform and the effect of noise immediately before the occurrence of a surge, and multiple surge occurrence points are calculated from the time of those surge arrival points and given priority. Since the order is displayed, priority is given to the point near the rise of the surge waveform as the surge arrival point when the influence of noise is small, and priority is given to the point where the influence of noise is small when there is a lot of noise influence. By using the surge arrival point, the surge occurrence point can be accurately determined.

  In addition, by judging the occurrence of a failure based on the failure current and the failure voltage, and distinguishing between the occurrence of a failure and a surge other than that (for example, induced lightning, etc.), information on surges that do not cause a failure can be prevented from being sent to the master station, or The master station can display the failure occurrence and other surges separately. As a result, it is possible to promptly check for surges that cause failures, and for surges that do not cause failures, accumulate the occurrence status history and check the transmission lines where there are frequent surges. Preventive maintenance becomes possible. Furthermore, the combination of the failure state flag and the maximum surge peak value can determine the lightning strike point of an overhead ground wire that does not cause a failure, thereby enabling maintenance of the overhead ground wire.

Also, by determining the priority order of the 1st to nth surge occurrence points according to the magnitude of the maximum surge peak value, surges are generated even in surge waveforms where noise increases as the maximum surge peak value increases. The point can be accurately positioned.
Also, by determining the priority order of the 1st to nth surge points according to the magnitude of the crest value of the fault current or fault voltage immediately after the fault occurs, the 1-wire ground fault, 2-wire short circuit, or 3-wire short circuit Even in surge waveforms where the noise immediately before the occurrence of a surge varies depending on the difference in failure, the surge occurrence point can be accurately determined.

  Furthermore, when the influence of noise immediately before the occurrence of a surge is small, and multiple surge occurrence points are calculated as the same point or a short distance point, among the surge occurrence points where the absolute value of the distance difference is a predetermined value or less, the priority order By adopting the average point of the surge occurrence points whose absolute value of the distance difference is not more than a predetermined value only for the highest surge occurrence point, a plurality of surge occurrence points can be narrowed down efficiently.

It is a block diagram which shows the structural example of the subunit | mobile_unit of the power transmission line fault location system which concerns on this invention. It is explanatory drawing which shows the operation | movement in the surge arrival point multiple detection means of FIG. It is a wave form diagram when a failure occurs immediately after the occurrence of a lightning surge. It is a block diagram which shows the structural example of the master station of the power transmission line fault location system which concerns on this invention. It is explanatory drawing which shows the example of operation | movement of the fault location system which concerns on this invention. It is explanatory drawing which shows the other example of operation | movement of the fault location system which concerns on this invention. It is explanatory drawing which shows the example of a structure and its operation | movement of a fault location system using the communication network of a mobile communication. It is principle explanatory drawing of the conventional surge orientation system. It is principle explanatory drawing of the transmission line fault location system proposed previously. It is explanatory drawing of the conventional fault location method. It is a wave form diagram which shows the example of a waveform of the surge by a lightning strike, and the surge by birds and beasts contact.

  The present invention will be described below with reference to the drawings. The transmission line fault location system according to the present invention includes a plurality of slave stations arranged at appropriate intervals in the main line or branch line end of the transmission line and in the middle of the line, and at least one master station.

  FIG. 1 is a block diagram showing a configuration example of a slave station of a transmission line fault location system according to the present invention. As shown in FIG. 1, the slave station includes GPS receiving means 11, fault current detecting means 12, fault voltage detecting means 13, current voltage monitoring means 14, surge arrival point multiple detecting means 15, and fault information transmitting means 16.

  The GPS receiving means 11 has a GPS antenna 11a and a GPS receiver 11b for receiving GPS signals from an artificial satellite (not shown). The GPS receiver 11b receives the encoded information transmitted from the artificial satellite, and generates a reset signal and current time every 1 second synchronized with the encoded information. Further, the GPS receiver 11b sends a reset signal to the control CPU 16a of the failure information transmitting means 16, and receives a time in nsec units less than 1 second which the control CPU 16a measures based on the reset signal. Further, when receiving the surge arrival point detection signal from the surge arrival point multiple detection means 15, the GPS receiver 11b sends the time at that time to the surge arrival point detection means 15 as a time of less than 1 msec display.

  The fault current detection means 12 includes a current sensor 12a that detects a current flowing through the transmission line, a filter 12b that extracts a commercial frequency component from the current detected by the current sensor 12a, and an A / D conversion that converts the output signal of the filter 12b into a digital signal 12c and a fault current detector 12d. The transmission current is acquired by the current sensor 12a, the filter 12b, and the A / D converter 12c, and the fault current detection unit 12d extracts the change in the transmission current as a fault current and compares it with a preset fault certification level. When the current exceeds a preset failure certification level, a failure occurrence signal based on the failure current is sent to the current voltage monitoring means 14. When a surge that causes an electrical failure occurs in the transmission line, the failure current exceeds the failure certification level, and therefore a failure occurrence signal is sent from the failure current detection unit 12d immediately after the occurrence of the surge. Further, the fault current detecting unit 12d sends fault current information such as the current value and phase angle of the fault current to the fault information transmitting means 16. This fault current information is stored in the memory 16b of the fault information transmitting means 16.

  The failure voltage detection means 13 is a voltage sensor 13a that detects a voltage generated in the transmission line, a filter 13b that extracts a commercial frequency component from the voltage detected by the voltage sensor 13a, and an A / D that converts the output signal of the filter 13b into a digital signal. It has a converter 13c and a fault voltage detector 13d. The transmission voltage is acquired by the voltage sensor 13a, the filter 13b, and the A / D converter 13c, and the failure voltage detector 13d extracts the change in the transmission voltage as a failure voltage and compares it with a preset failure certification level. When the voltage exceeds a preset failure certification level, a failure occurrence signal based on the failure voltage is sent to the current voltage monitoring means. When a surge that causes an electrical failure occurs in the transmission line, the failure voltage exceeds the failure certification level, and therefore a failure occurrence signal is sent from the failure voltage detection unit 13d immediately after the occurrence of the surge. Further, the fault voltage detection unit 13d sends fault voltage information such as the voltage value and phase angle of the fault voltage to the fault information transmission means 16. This failure voltage information is also stored in the memory 16b of the failure information transmitting means 16.

  Each slave station can include a plurality of fault current detection means 12 and fault voltage detection means 13. It is also possible to provide a plurality of failure recognition levels in the failure current detection means 12 and the failure voltage detection means 13 so as to convey the details to the current voltage monitoring means 14 to the extent of the failure state.

  The current / voltage monitoring unit 14 changes the failure state flag when receiving a failure occurrence signal from at least one of the failure current detection unit 12 and the failure voltage detection unit 13, and the failure state flag is passed through the surge arrival point multiple detection unit 15. To the failure information sending means 16. For example, assuming that the normal failure state flag is “0” of 1 bit, when a failure occurrence signal is received, the failure state flag becomes “1” and a failure state flag of “1” is transmitted. When a plurality of failure certification levels are provided in the failure current detection means 12 and the failure voltage detection means 13, a plurality of failure status flags or a plurality of failure flags may be set correspondingly.

  The surge arrival point multiple detection means 15 includes a surge sensor 15a, a filter 15b, a surge detection threshold unit 15c, a comparator 15d, an A / D converter 15e, and a surge arrival point multiple detection unit 15f. The surge arrival point multiple detection unit 15f includes a surge waveform storage unit 15f-1, a peak detection unit 15f-2, a comparison setting unit 15f-3, and a surge arrival point calculation unit 15f-4 that calculates the first and second surge arrival points. Have

  The surge sensor 15a detects a surge waveform generated in the power transmission line, and the filter 15b converts the surge waveform detected by the surge sensor 15a into a voltage that can be processed by the electronic circuit, and extracts a high-frequency component. The surge detection threshold value unit 15c sets a surge detection threshold value VTH that can detect even a small level surge due to contact with birds and beasts, and the comparator 15d sets the output signal of the filter 15b and the surge detection threshold value VTH set by the surge detection threshold value unit 15c. In comparison, when the output signal of the filter 15b becomes larger than the surge detection threshold VTH, an output to that effect is sent to the surge waveform storage unit 15f-1 of the surge arrival point multiple detection unit 15f. The A / D converter 15e converts the output signal of the filter 15b into a digital signal.

  The surge waveform storage unit 15f-1 repeatedly overwrites and records the output signal of the A / D converter 15e for a preset time.When the output of the comparator 15c is received, the surge level is set to the surge detection threshold VTH. The output signal of the A / D converter 15e for a preset time before and after the point of time is held. The recording time before and after the point when the surge level becomes the surge detection threshold VTH may not be the same.

  The peak detection unit 15f-2 detects the maximum peak value of the signal (surge waveform (digital)) held in the surge waveform storage unit 15f-1. The comparison setting unit 15f-3 sets first and second ratios R1 and R2 for multiplying the maximum peak value detected by the peak detection unit 15f-2. Note that one of the first and second ratios R1, R2, for example, the ratio R2 is the level when the maximum peak value of the surge waveform is multiplied by the ratio, and the influence of noise based on experience from the past surge waveform. Is set to a small level, and the other ratio R1 is set so that the level obtained by multiplying the maximum peak value of the surge waveform by the ratio is the level near the rising point of the surge waveform. .

  The surge arrival point calculation unit 15f-4 is the earliest among the multiple points at which the surge waveform has a level obtained by multiplying the maximum peak value by the ratio R1, between the surge waveform recording start point and the maximum peak value point. The zero crossing point at which the straight line passing through two points near the point SP1 where it occurs intersects the zero level of the surge waveform is calculated as the first surge arrival point PT1, and the surge waveform multiplies its maximum peak value by the ratio R2. The zero crossing point where the straight line that passes between the two points near the point SP2 that occurred the first time between the surge waveform recording start point and the point at the maximum peak value intersects the zero level of the surge waveform. Is calculated as the second surge arrival point PT2.

  The surge arrival point multiple detection means 15 sends the generated signals of the first and second surge arrival points PT1 and PT2 to the GPS reception means 11, receives the times T1 and T2 at which they occurred, The fault value is sent to the fault information sending means 16 together with the maximum peak value and the fault status flag sent from the current voltage monitoring means 14. The occurrence times T1 and T2 of the first and second surge arrival points PT1 and PT2 are output to the surge waveform storage unit 15f-1 when the output signal of the filter 15b becomes larger than the surge detection threshold VTH. It can be calculated from the number of samplings of the surge waveform up to the zero level point starting from that time and receiving the time at which it occurred from the GPS receiving means 11. The comparison between the surge and the surge detection threshold value VTH may be performed in the surge arrival point multiple detection unit 15f.

  The failure information transmission means 16 includes the surge arrival point detection times T1, T2 sent from the surge arrival point multiple detection means 15, the surge maximum peak value and the failure state flag, and the current value of the failure current sent from the failure current detection means 12. CPU 16a for controlling transmission of fault information such as voltage value and phase of fault voltage sent from phase and fault voltage detection means 13, memory 16b for temporarily storing data such as fault information, fault information An optical modem 16c for transmitting to the parent station through the optical fiber 17 in the overhead ground line (OPGW) is provided, and failure information is transmitted to the parent station.

  The structure and operation of the master station will be described in detail later. However, if there is noise before the surge occurs in the master station, the surge occurrence point calculated from the time of the surge arrival point PT2 where the influence of noise is small If there is no noise before the occurrence of a surge, priority is given to the surge occurrence point calculated from the time of the surge arrival point PT1 close to the rise of the surge waveform.

  As failure information, a surge waveform, a failure current waveform, and a failure voltage waveform may be stored in the memory 16b and transmitted to the master station. Further, the optical modem 16c may be changed to a mobile phone, a wireless modem, a satellite communication radio, or the like, and failure information may be transmitted to the master station using the communication network.

  Next, the operation of surge detection in the slave station having the above configuration will be described. FIG. 2 is an explanatory view showing the operation in the surge arrival point plural detecting means 15.

  In the surge arrival point multiple detection means 15, the digital value of the surge waveform is sent from the A / D converter 15e to the surge waveform storage unit 15f-1. The surge waveform storage unit 15f-1 repeatedly overwrites and records the output of the A / D converter 15e for a certain time, for example, 10 msec, in which the surge waveform can be reliably recorded, and the output signal of the filter 15b is the surge detection threshold unit 15d When the comparator 15c detects that the surge detection threshold value VTH has been set, the overwrite recording is stopped. Thereby, before and after the time when the comparator 15c sends out the output, for example, a surge waveform of 5 msec before and after is held in the surge waveform storage unit 15f-1.

  The peak detection unit 15f-2 searches the entire period of the surge waveform held in the surge waveform storage unit 15f-1 to find the maximum peak point, and determines the maximum peak point value and the time thereof as the surge arrival point calculation unit 15f. Sent to -4. The time of the maximum peak point can be calculated from the number of surge waveform samplings from the waveform recording start point.

  In the surge arrival point calculation unit 15f-4, a value obtained by multiplying the maximum peak value by the first ratio R1 (for example, 10%) and the second ratio R2 (for example, 50%) preset in the ratio setting unit 15f-3 Are searched from the waveform recording start point to the maximum peak point, and the points SP1 and SP2 closest to the waveform recording start point are obtained.

  In Fig. 2, the ratio R1 is set so that the level obtained by multiplying the maximum peak value of the surge waveform by the ratio is the level close to the rise of the surge waveform, and the ratio R2 is set to the maximum peak value of the surge waveform. Is set so that the influence of noise is reduced from experience in the past surge waveform. Then, the zero cross point where the straight line passing through the two points in the vicinity of the points SP1 and SP2 intersects the zero level of the surge waveform is calculated as the surge arrival points PT1 and PT2.

  FIG. 3 is a waveform diagram when an electrical failure occurs immediately after a lightning strike.

  When the lightning strike surge exceeds the surge detection threshold VTH, the surge arrival point multiple detection means 15 sends the surge arrival point detection signal from the surge arrival point multiple detection unit 15f to the GPS reception means 11, and the time (surge arrival point time) ) Receive T1 and T2. Then, the times T1, T2 and the maximum surge peak value are sent to the failure information transmitting means 16.

  The fault current detection means 12 uses the current flowing through the transmission line as a fault current, and when the change in the fault current exceeds the fault certification level, sends a fault occurrence signal to the current voltage monitoring means 14 as a fault has occurred. Further, the fault current detection means 12 sends the current value and phase angle of the fault current to the fault information transmission means 16.

  The failure voltage detection means 13 uses the voltage generated in the transmission line as a failure voltage, and sends a failure occurrence signal to the current voltage monitoring means 14 that a failure has occurred when the change in the failure voltage exceeds the failure certification level. The failure voltage detection means 13 sends the current value and phase angle of the failure voltage to the failure information transmission means 16.

  When the current / voltage monitoring means 14 receives a failure occurrence signal from at least one of the failure current detection means 12 and the failure voltage detection means 13, the failure state flag which is “0” in the normal state is set to “1” and a plurality of surge arrival points It is sent to the detection means 15.

  The failure information transmission means 16 includes the surge arrival point times T1, T2 sent from the surge arrival point multiple detection means 15, the surge maximum peak value and the failure state flag, the current value of the failure current sent from the failure current detection means 12, and The voltage value and phase angle of the fault voltage sent from the phase angle and fault voltage detection means 13 are temporarily stored in the memory 16B and sent to the master station as fault information. The failure information may include a surge waveform, a failure current waveform, and a failure voltage waveform.

  FIG. 4 is a block diagram showing a configuration example of a master station of the transmission line fault location system according to the present invention. As shown in FIG. 4, the master station has a failure information receiving means 21, a surge occurrence point multiple calculation processing means 22, a surge occurrence point priority order processing means 23, a failure point display selection processing means 24, a monitor 25, and a power transmission line database 26. Is provided. The failure information receiving means 21 includes an optical modem 21a, a data formation processing unit 21b, and a slave station selection processing unit 21c.

  In the transmission line database 26, information on installed transmission lines and slave stations is stored in advance. This information includes, for example, the slave station number, the length of the transmission line between the slave stations, the branch tower number, the length of the transmission line between the branch tower and the adjacent slave station.

  The master station is built in a personal computer, and the surge occurrence point multiple calculation processing means 22, surge occurrence point priority order processing means 23, and failure point display selection processing means 24 can be configured as hardware or software. When configured as software, each process is called and executed by the central processing unit.

  Next, the operation in the master station having the above configuration will be described. The optical modem 21a of the failure information receiving means 21 receives the failure information transmitted from each slave station via the optical fiber 17 in the overhead ground wire, and the data formation processing unit 21b converts the failure information. The data is sent to the slave station selection processing unit 21c.

  The slave station selection processing unit 21c selects a slave station to be used by the surge occurrence point multiple calculation processing means 22 based on the failure information. Here, for example, the slave stations are grouped based on the current value and the phase angle of the fault current, and the slave stations used by the surge occurrence point multiple calculation processing means 22 are selected from the slave stations in each group. When the slave stations are grouped in two, it is only necessary to select the slave station with the earliest surge arrival time T1, T2 in each group, and when the slave stations are grouped into three or more. In each group, select the slave station with the earliest surge arrival time T1, T2, respectively, and then select two or three of the selected slave stations from the earliest surge arrival time T1, T2 respectively. Just choose. The surge station number calculation processing means 22 is notified of the slave station number of the selected slave station.

  The surge occurrence point multiple calculation processing means 22 includes first surge occurrence point calculation processing means 22a and second surge occurrence point calculation processing means 22b. When the slave station selection processing unit 21c selects two slave stations for surge arrival point times T1 and T2, the first surge occurrence point calculation processing means 22a uses the surge arrival point times T1 group of the two selected slave stations. The first surge occurrence point is calculated using the above equation (1), and the second surge occurrence point calculation processing means 22b uses the surge arrival time T2 group to determine the second surge occurrence point using the above equation (1). calculate. In this calculation, information stored in the transmission line database 26 is also used. Further, when the slave station selection processing unit 21c selects three slave stations for each of the surge arrival time points T1 and T2, the combination of all three for each of the surge arrival time points T1 and T2 (1 ) To calculate the surge occurrence point and use the average of the two surge occurrence points close to the surge occurrence point as the first surge occurrence point, or of the two surge occurrence points near the surge occurrence point. The smaller difference may be used as the first surge occurrence point.

  The surge occurrence point priority order processing means 23 gives priority to the first surge occurrence point and the second surge occurrence point according to a predetermined condition. Examples of the predetermined conditions are shown below.

  (1) Predetermined condition 1: When the magnitude of the maximum surge peak value is larger than a preset threshold value (first priority order decision value), the second surge occurrence point is set as the first candidate, and the first surge occurrence point is set as the first 2 candidates. Conversely, when the magnitude of the maximum surge peak value is equal to or less than the first priority order determination value, the first surge occurrence point is set as the first candidate, and the second surge occurrence point is set as the second candidate. When priorities are assigned according to the predetermined condition 1, the maximum surge peak value or surge waveform is also transmitted as failure information from the slave station. The first priority order determination value may be determined from the relationship between the maximum surge peak value in the past data and the noise generation status immediately before the occurrence of the surge. Further, at least one of the first priority order determination value and the priority order may be appropriately changed.

  In the example of the lightning surge waveform shown in FIG. 11, since the noise immediately before the occurrence of the surge is large and the maximum peak value of the surge is 5000, if the first priority determination value is set to a value slightly smaller than 5000, the influence of the noise The second surge occurrence point with a small can be selected as the first candidate.

  (2) Predetermined condition 2: If the magnitude of the peak value of the fault current or fault voltage is greater than a preset threshold value (second priority order decision value), the second surge occurrence point is the first candidate and the first surge The point of occurrence is the second candidate. Conversely, if the magnitude of the peak value of the fault current or fault voltage is equal to or less than the second priority order determination value, the first surge occurrence point is set as the first candidate, and the second surge occurrence point is set as the second candidate. When priorities are given according to the predetermined condition 2, a fault current or fault voltage waveform or peak value is transmitted as fault information from the slave station. The second priority order determination value may be determined from the relationship between the peak value of the fault current or fault voltage in the past data and the noise generation status immediately before the occurrence of the surge. Also, in the 1-wire ground fault and other faults (for example, 2-wire ground fault, etc.), the noise immediately before the occurrence of a surge in a 1-wire ground fault tends to be small, so the second priority order decision value is set to 1. It may be a line ground fault current value or a voltage value. Furthermore, at least one of the second priority order determination value and the priority order may be changed as appropriate.

  If the absolute value of the distance difference between the first surge occurrence point and the second surge occurrence point calculated by the surge occurrence point multiple calculation processing means 22 is within a preset distance (single display distance), Only one candidate surge occurrence point or an average of the first and second candidate surge occurrence points may be employed. Thereby, when the influence of noise immediately before the occurrence of a surge is small, it is possible to efficiently narrow down a plurality of surge occurrence points calculated as the same point or a point at a close distance.

  Note that the predetermined conditions 1 and 2 can be used alone or in combination. When used in combination, if the first surge occurrence point is the first candidate under any of the predetermined conditions, it can be given priority. That's fine.

  When the failure point display selection processing means 24 receives the first and second candidate surge occurrence points from the surge occurrence point priority order processing means 23, it generates a surge together with the priority assigned by the surge occurrence point priority order processing means 23. If a point is displayed and only the first candidate surge point is received, only that surge point is displayed.

  The failure point display selection processing means 24 checks the failure status flags of all the slave stations, and if the failure status flag is “1” even in one slave station, displays the surge occurrence point on the monitor 25 as the failure point. Urge the user to perform an emergency check. However, if the failure status flags of all the slave stations are “0”, the surge occurrence point is displayed on the monitor 25 as a surge caused by an induced lightning that does not cause an electrical failure, and a surge such as an induced lightning other than the occurrence of a failure is displayed. Is displayed separately from the surge that caused the failure.

  The master station can record the surge occurrence point and the occurrence time each time it receives the failure information due to the occurrence of surge and calculates the surge occurrence point, and keeps it as a history. As a result, statistical processing can be performed after a predetermined period of time, and graphs and numerical values can be displayed for the location and surge level of failure points, overhead lightning strike points, and other surge occurrence points. For surges that do not occur, frequent inspections can be performed at a later date.

  Hereinafter, the operation of the fault location system composed of the slave station and the master station having the above configuration will be described with a specific example. FIG. 5 is an example of the power transmission line 1 having power sources at the electric stations A and B. Here, the master station 2 is installed at the electric power station A, the slave stations 3 to 7 are installed at an appropriate interval on the transmission line 1, and the master station 2 and the slave stations 3 to 7 are connected by an optical fiber in the overhead ground wire. Suppose that

  Assuming that a surge occurs at a point F1 of the transmission line 1 and a failure occurs, the surge propagates from the point F1 to each end of the transmission line 1. The fault currents Ig1 and Ig2 flow from the electric stations A and B where the power source is located toward the point F1. FIG. 5 shows the maximum surge peak value and the current value and phase of the fault current at each slave station position of the transmission line 1. In addition, surge arrival times T1 and T2 detected by the slave stations 3 to 7 as described above are also shown. These are detected by the surge arrival point multiple detection means 15 included in each of the slave stations 3-7. The slave stations 3 to 7 transmit the failure information generated as described above to the master station 2 (electricity station A) through the optical fiber in the overhead ground wire.

  When the master station 2 receives the fault information, the master station 2 groups the slave stations 3 to 7 according to a predetermined condition based on the current value and phase angle of the fault current. This grouping is performed by the slave station selection processing unit 21c (FIG. 4). In this example, the slave stations 3 and 4 (A group) having a current value of 200A and a phase angle of 0 ° are grouped into slave stations 5 to 7 (B group) having a current value of 200A and a phase angle of 180 °.

  Then, the surge arrival point times T1 in the groups A and B are compared, rearranged in the order of the times, and the slave station with the earliest surge arrival point time in each group A and B is selected. Here, the slave station 4 is selected in the A group, and the slave station 5 is selected in the B group. As a result, the slave station numbers of the slave stations 4 and 5 selected and the surge arrival times T1 and T2 in the slave stations 4 and 5 are sent to the surge occurrence point multiple calculation processing means 22.

  In the surge occurrence point multiple calculation processing means 22, the first surge occurrence point FP1 is calculated by the above equation (1) from the surge arrival time T1 group of the slave station selected by the slave station selection processing unit 21c, and the surge arrival time The second surge occurrence point FP2 is calculated from the T2 group by the above equation (1). In the example of FIG. 5, the absolute values of the first and second surge occurrence points FP1 and FP2 (distance from the slave station 4 to the surge occurrence point) and the distance difference between FP1 and FP2 are the surge arrival times of the slave stations 4 and 5. It is calculated as follows from the T1 group and the T2 group.

FP1 = (10 + c (18.3μsec-15.0μsec)) / 2 = 5.495km
FP2 = (10 + c (20.0μsec-13.3μsec)) / 2 = 6.005km
｜ FP1−FP2 ｜ = 0.510km

  The surge occurrence point priority order processing means 23 gives priority to the first surge occurrence point FP1 and the second surge occurrence point FP2 in accordance with a predetermined condition. In the example of FIG. 5, the maximum surge peak value in the slave stations 3 to 7 is 5500, and the first priority order determination value is 5000. In this case, since the maximum surge peak value 5500 is larger than the first priority order determination value 5000, the second surge occurrence point FP2 becomes the first candidate, and the first surge occurrence point FP1 becomes the second candidate. If the absolute value of the distance difference between the first surge occurrence point FP1 and the second surge occurrence point FP2 is a preset distance (single display distance), for example, within 300 m, only the first candidate surge occurrence point, or The average point of the first and second candidate surge occurrence points is adopted, but here the absolute value of the distance difference between the first surge occurrence point FP1 and the second surge occurrence point FP2 is 510 m (> 300 m), Two points, the first candidate surge occurrence point FP2 (6.005 km) and the second candidate surge occurrence point FP1 (5.495 km), are sent to the failure point display selection means 24.

  The failure point display selection processing means 24 checks the failure status flags of all the slave stations sent from the failure information receiving means 21, and if at least one failure status flag is “1”, the surge occurrence point multiple calculation processing means 22 The point of occurrence of the surge sent from is set as the failure point, the first candidate and the second candidate are displayed on the monitor 25, and the user is urged to perform an emergency check. In the example of FIG. 5, since a fault current has occurred and the fault status flag is “1”, the first candidate surge occurrence point FP2 (6.005 km) and the second candidate surge occurrence point FP1 (5.495 km) 2 points are displayed as failure points.

  When the failure status flags of all the slave stations are “0”, the first and second candidate surge occurrence points are displayed as the occurrence of the surge without urgency other than the occurrence of the failure. Compare the peak value of the surge other than the occurrence of failure with a predetermined value (electric shock determination level), and if the surge exceeds the electric shock determination level even in one of the slave stations, the overhead ground wire electric shock A surge occurrence point can also be displayed as a point.

  FIG. 6 is an explanatory diagram showing another example of the operation of the fault location system. In this example, the absolute value of the difference between the first and second surge occurrence points FP1, FP2 (distance from the slave station 4 to the surge occurrence point) and the distance between FP1 and FP2 is the surge arrival time T1 of the slave stations 4, 5. It is calculated as follows from the group and the T2 group.

FP1 = (10 + c (19.2μsec-14.2μsec)) / 2 = 5.750km
FP2 = (10 + c (20.0μsec-13.3μsec)) / 2 = 6.005km
｜ FP1−FP2 ｜ = 0.255km

  Also in this case, since the maximum surge peak value 5500 is larger than the first priority determination value 5000, the second surge occurrence point FP2 becomes the first candidate and the first surge occurrence point FP1 as in the example of FIG. Becomes the second candidate. However, if the absolute value (255m) of the distance difference between the first surge point FP1 and the second surge point FP2 is within a single display distance of 300m, the first candidate surge point FP2 (6.005km), or Only one of the average points (5.8775 m) of the first and second candidate surge occurrence points FP1 and FP2 is sent to the failure point display selection means 24.

  The failure point display selection processing means 24 checks the failure status flags of all the slave stations sent from the failure information receiving means 21, and if at least one failure status flag is “1”, the surge occurrence point multiple calculation processing means 22 Is displayed on the monitor 25 as a failure point to urge the user to perform an emergency inspection. In the example of FIG. 6, since a fault current has occurred and the fault status flag is “1”, the first candidate surge occurrence point FP2 (6.005 km) or the first and second candidate surge occurrence points FP1. Therefore, the average point (5.8775m) of FP2 is displayed as the failure point.

  In the above embodiment, failure information is transmitted / received via the optical fiber 17 in the overhead ground wire. However, a mobile packet communication network can be used to transmit / receive failure information.

  FIG. 7 shows an example of the configuration and operation of a fault location system that uses a mobile packet communication network to locate faults in the transmission line 1 where the power stations A and B have power supplies and do not have branches. Indicates. In FIG. 7, the slave stations 3 to 7 are installed in the power transmission line 1 at appropriate intervals. In this case, the slave station is different from that in FIG. 1 in that a radio for mobile packet communication is used instead of the optical modem of the failure information transmitting means, and the master station is different from that in FIG. However, the portable terminal device 8 is used instead of the optical modem. Since other configurations are basically the same, the specific configurations of the slave station and the master station are not shown, and will be described below using the same reference numerals as those in FIGS.

  Assuming that a short-circuit failure has occurred at point F2, the surge propagates from the point F2 to each end, and the failure current flows from the electric stations A and B where the power supply is located toward the point F2. Each of the slave stations 3 to 7 detects a surge, a fault current, and a fault voltage, and transmits fault information to the master station 2 via the mobile packet communication network.

  The mobile terminal device 8 on the master station 2 side receives the failure information transmitted from the slave stations 3 to 7, and the slave station selection processing unit 21c is a slave station 3 to 5 with a current value of 5500 A and a phase angle of 0 ° ( (Group A) and grouped into slave stations 6 and 7 (Group B) having a current value of 3000A and a phase angle of 180 °. Then, the surge arrival point times T1 in the groups A and B are compared, rearranged in the order of the times, and the slave station with the earliest surge arrival point time in each group A and B is selected. Here, the slave station 5 is selected in the A group, and the slave station 6 is selected in the B group. As a result, the slave station numbers of the slave stations 5 and 6 selected and the surge arrival times T1 and T2 in the slave stations 5 and 6 are sent to the surge occurrence point multiple calculation processing means 22.

  In the surge occurrence point multiple calculation processing means 22, the first surge occurrence point FP1 is calculated by the above equation (1) from the surge arrival time T1 group of the slave stations 5 and 6 selected by the slave station selection processing unit 21c, The second surge occurrence point FP2 is calculated from the surge arrival time T2 group by the above equation (1), and is sent to the surge occurrence point priority order processing means 23.

  The surge occurrence point priority order processing means 23 gives priority to the first surge occurrence point FP1 and the second surge occurrence point FP2 according to a predetermined condition, and sends them to the failure point display selection means 24. In the example shown in FIG. 7, if the first priority order decision value is 200A, the short circuit current maximum value for the slave stations 3 to 7 is 5500A, which is larger than the first priority order decision value 200A. FP2 becomes the first candidate, and the first surge occurrence point FP1 becomes the second candidate. When the absolute value of the distance difference between the first surge occurrence point FP1 and the second surge occurrence point FP2 is a preset distance (single display distance), for example, within 300 m, the surge occurrence point priority order processing means 23 is: Only the first candidate surge occurrence point or the average of the first and second candidate surge occurrence points is adopted and sent to the failure point display selection means 24.

  The failure point display selection processing means 24 checks the failure status flags of all the slave stations sent from the failure information receiving means 21, and if any failure status flag is "1", the surge occurrence point multiple calculation processing means 22 The surge occurrence point sent out from is displayed as a failure point on the monitor 25 with priorities of the first candidate and the second candidate, and prompts the user for an emergency check.

  Although the embodiment has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the surge arrival point and the surge occurrence point are two, but the ratio of multiplying the maximum peak value of the surge waveform is three or more, and three or more surge arrival points and surge occurrence points are calculated. You may do it. In this case as well, the surge occurrence points may be prioritized according to predetermined conditions according to the maximum surge peak value, the peak value of the fault current, or the fault voltage.

  In the above embodiment, the failure information including the failure status flag is transmitted from the slave station, and the master station assigns a priority order and distinguishes whether the failure has occurred or not according to the failure status flag. However, if the failure status flag does not indicate a failure status, the failure information is not transmitted from the slave station.The master station receives failure information only when a failure occurs and determines the surge occurrence point. It may be displayed. In this case, failure information due to surges such as induced lightning need not be transmitted to the master station.

  Wireless communication such as satellite communications and mobile phones has a fee structure in which packet charges are added to the basic charge, and the communication cost increases as the amount of communication data and the number of communication increases. By making it possible to select information to be transmitted with reference to the failure state flag in the slave station and transmitting only particularly necessary information, it is possible to suppress an increase in communication cost. For example, if failure information is transmitted only when a failure occurs, only a few failures occur annually, so that packet charges become insignificant and communication costs can be greatly reduced.

  1,31 ... Transmission line, 2,33,42 ... Master station, 3-7,34,43-50 ... Slave station, 8 ... Mobile terminal device, 11 ... GPS receiving means 11a ... GPS antenna 11a, 11b ... GPS receiver, 12 ... failure current detection means, 12a ... current sensor, 12b, 13b, 15b ... filter, 12c, 13c, 15e ... A / D converter, 12d: Fault current detection unit, 13: Fault voltage detection means, 13a: Voltage sensor, 13d: Fault voltage detection unit, 14 ... Current voltage monitoring means, 15: Multiple surge arrival point detection means, 15a: Surge sensor, 15c: Surge detection threshold, 15d: Comparator, 15f: Multiple surge arrival point detector, 16: Failure information Transmitting means, 16a ... control CPU, 16b ... memory, 16c, 21a ... optical modem, 21 ... failure information receiving means, 21b ... data formation processing unit, 21c ... child station Selection processing unit, 22 ... Surge generation point multiple calculation processing 23 ... Surge generation point priority order processing means 24 ... Failure point display selection processing means 25 ... Monitor 26 ... Transmission line database 32, A to D ... Electricity station

Claims (6)

A failure point locating system having a plurality of slave stations arranged on a transmission line and transmitting failure information of the transmission line to a parent station, and a parent station for locating a failure point based on the failure information transmitted from the slave station In
The slave station is
GPS receiving means for receiving GPS radio waves from an artificial satellite and extracting the current time held by GPS;
Fault current detection means for detecting fault current flowing in the transmission line and sending fault current information;
Fault voltage detection means for detecting fault voltage generated in the transmission line and sending fault voltage information;
Current voltage monitoring means for sending a failure state flag corresponding to a failure occurrence state based on at least one of failure current information and failure voltage information;
Having a surge detection means, and when the surge exceeds a preset surge detection threshold, a surge waveform is recorded for a predetermined period before and after that point, and in the recorded surge waveform, the maximum peak value and a predetermined first To the nth (n is an integer equal to or greater than 2) ratio, and among the multiple points, a point that is between the surge waveform recording start time and the maximum peak time point and that occurs first is determined for each ratio. The first to n-th surge arrival time is detected by taking the time from the GPS receiving means as the first to n-th surge arrival points as straight zero-cross points passing through two points on the nearby surge waveform. Means for detecting multiple surge arrival points;
The first to nth surge arrival time, the fault current information and the fault voltage information are set as fault information, and the fault information is transmitted to the master station according to a fault status flag, or the fault Comprising failure information transmitting means configured to transmit the information including a failure state flag,
The master station is
Fault information receiving means for receiving fault information transmitted from the plurality of slave stations and selecting a slave station to be used for orientation based on the fault information;
A plurality of surge occurrence point calculation processing means for calculating the first to nth surge occurrence points according to the time differences of the first to nth surge arrival point times in the slave stations selected by the failure information receiving means;
When the failure information is transmitted from the failure information transmission means according to the failure flag, the first to nth surge occurrence points are displayed as failure points with priorities assigned according to predetermined conditions. When failure information including a failure state flag is transmitted from the failure information transmission means, priorities are set according to predetermined conditions, and a failure occurrence and other surges are determined according to the failure state flag. A failure point locating system comprising surge occurrence point priority order processing means for distinguishing and displaying first to nth surge occurrence points.   The surge occurrence point priority order processing means determines whether the magnitude of the surge maximum peak value is greater than (n−1) first priority order decision values set in advance as a predetermined condition. The failure point locating system according to claim 1, wherein priorities are assigned to the surge occurrence points.   The fault location system according to claim 2, wherein at least one of the first priority order determination value and the priority order is variable.   The surge occurrence point priority order processing means determines whether the magnitude of the peak value of the fault current or fault voltage is larger than (n−1) second priority order decision values set in advance as a predetermined condition. The failure point locating system according to claim 1, wherein priorities are assigned to the n th surge occurrence points.   5. The fault location system according to claim 4, wherein at least one of the second priority order determination value and the priority order is variable.   The surge occurrence point priority order processing means sets the first to nth surge occurrence points according to a predetermined condition when an absolute value of a difference between at least two distances of the first to nth surge occurrence points exceeds a predetermined value. If the absolute value of the distance difference between the first to nth surge occurrence points is less than or equal to a predetermined value, only the surge occurrence point with the highest priority or the first to nth surges are displayed. 6. The fault location system according to claim 1, wherein an average of the occurrence points is displayed.