JP5602082B2 - Short-circuit locating device, short-circuit locating method and program - Google Patents

Description

  The present invention relates to a short circuit point locating device, a short circuit point locating method, and a program.

  When a short circuit accident occurs in the distribution line, it is necessary to identify the short circuit point for repair. For example, in Patent Document 1, an accident section is determined based on operation information of a protective relay or a circuit breaker.

JP 2001-016766 A

  However, even if the accident section is specified based on the operation of the circuit breaker or the like, the distance between the circuit breakers is often long. The worker needs to actually patrol the entire section, and there is a need to locate the short-circuit point with higher accuracy.

  This invention is made | formed in view of such a background, and it aims at providing the short-circuiting point location apparatus, the short-circuiting point location method, and program which can pinpoint a short-circuiting point accurately.

  A main invention of the present invention for solving the above problems is a device for locating a short-circuit point in a three-phase three-wire distribution line, wherein the distribution line is composed of two single-phase transformers, A voltage drop rate acquisition unit that acquires a voltage drop rate at each of the connection points of the transformer to the distribution path, in which a plurality of transformers with different combinations of four wires to which one single-phase transformer is connected are connected. And a short-circuit type determination unit that determines whether a three-phase short circuit or a single-phase short circuit is determined depending on whether the rate of descent is larger as the line length from the feeder that supplies power to the distribution line is longer. A short-circuit distance calculation unit that calculates a distance from the connection point to the short-circuit point based on the drop rate according to whether the short-circuit or the single-phase short-circuit.

  According to the short-circuit point locating device of the present invention, it is possible to determine whether it is a three-phase short circuit or a single-phase short circuit based on voltage drop rates at a plurality of locations. Moreover, according to the short circuit point location apparatus of this invention, a short circuit point can be determined on the basis of a connection point. Therefore, by using a location closer to the short-circuit point as a reference, the accuracy of the short-circuit point location can be increased.

Further, in the short-circuit point locating device of the present invention, the short-circuit distance calculating unit changes the line length, and calculates a percent impedance and an impedance from the connection point to the short-circuit point based on the changed line length. In the case of a three-phase short circuit, the short-circuit current is calculated by multiplying the quotient obtained by dividing the rated current by the percent impedance by 100, and the line-side voltage drop at the short-circuit point is calculated by multiplying the short-circuit current, the impedance, and the square root of 3. In the case of a single-phase short circuit, the short circuit current is calculated by dividing the quotient obtained by dividing the rated current by the percent impedance by 100 and 3 by the square root of 2, and calculating the short circuit current, the impedance, and 2 To calculate the line-side voltage drop, calculate the voltage change rate based on the line-side voltage drop, the voltage change rate is The line length that matches the serial descent rate, may be calculated as the distance from the connection point to the short-circuit point.
In this case, since the resistance, reactance, and the like in the distribution path and the power source are known, the short-circuit distance can be easily calculated by using, for example, the percent impedance method when the voltage drop rate is used. Moreover, since the short-circuit distance can be calculated using an appropriate calculation formula depending on whether it is a three-phase short circuit or a single-phase short circuit, the short-circuit point can be determined with higher accuracy.

The short-circuit point locating device of the present invention further includes a power failure determination unit that determines whether or not a power failure has occurred at the connection point based on the descent rate, and the short-circuit distance calculation unit includes a three-phase short circuit and When it is determined, only the distance from the connection point closest to the connection point where the power failure has occurred and from the connection point where the power failure has not occurred may be calculated.
In the case of a three-phase short-circuit, a power failure occurs on the load side from the short-circuit point. Therefore, the accuracy of short-circuit point location can be increased by using the closest location among the measurement points where no power failure has occurred.

  Further, in the short-circuit point locating device of the present invention, when the short-circuit distance calculation unit is determined to be a single-phase short-circuit, among the first connection points that are the connection points, the first connection point is The difference between the rate of descent and the rate of descent for the second connection point of the line length that is the second longest after the first connection point is specified to exceed a predetermined threshold, and the specified first You may make it calculate the said distance from the said connection point to the said short circuit point only about a connection point.

  Further, in the short-circuit point locating device of the present invention, connected to the transformer, is connected to a voltage measuring device that measures the voltage output from the transformer, and is communicably connected. The voltage may be acquired from a voltage measuring device, and the drop rate may be calculated based on the acquired voltage.

  Further, in the short-circuit point locating device of the present invention, the voltage drop rate acquisition unit is connected to the transformer to be communicably connected to the voltage measurement device for measuring the drop rate, and the voltage drop rate acquisition unit is connected to the voltage drop from the voltage measurement device. You may make it acquire a rate.

In the short-circuit point locating device of the present invention, the voltage measuring device may be a watt-hour meter having a communication function.
In this case, since many watt-hour meters (smart meters) having a communication function are connected to the distribution path, the short-circuit point can be accurately determined by using the connection point as a reference.

Further, the short-circuit point locating device of the present invention is, for each connection point, a facility information storage unit that stores a target point in the distribution path and a target point distance that is a distance from the target point to the connection point, The target point corresponding to the connection point and the target point distance are read from the facility information storage unit, a standardization distance that is a distance obtained by adding the distance to the read target point distance is calculated, and the standardization is calculated from the target point You may make it further provide the short circuit point location part which normalizes the point of distance as the said short circuit point.
In this case, the short-circuit point can be determined by the distance from the target point on the distribution path. Therefore, the operator who performs the repair of the short circuit can use the target point as a reference, and can easily grasp the short circuit point.

  Another aspect of the present invention is a method of locating a short-circuit point in a three-phase three-wire distribution line, wherein the distribution line includes two single-phase transformers, and the two single-phase transformers are A plurality of transformers with different combinations of four wires to be connected are connected, and the computer obtains the voltage drop rate at each of the connection points of the transformer to the distribution line and supplies power to the distribution line. Depending on whether the drop rate is larger as the line length from the feeder to the transformer is longer, it is determined whether it is a three-phase short circuit or a single-phase short circuit. Based on this, the distance from the connection point to the short-circuit point is calculated.

  Another aspect of the present invention is a program for locating a short-circuit point in a three-phase three-wire distribution line, wherein the distribution line includes two single-phase transformers, and the two single-phase transformers A plurality of transformers with different combinations of four wires to which a transformer is connected, a step of acquiring a voltage drop rate at each of connection points of the transformer to the distribution path, and the distribution path Depending on whether the drop rate is larger as the line length from the feeder that supplies power to the transformer is longer, it is determined whether it is a three-phase short circuit or a single-phase short circuit, and depending on whether it is a three-phase short circuit or a single-phase short circuit And calculating a distance from the connection point to the short-circuit point based on the descent rate.

  Other problems and solutions to be disclosed by the present application will be made clear by the embodiments of the invention and the drawings.

  According to the present invention, it is possible to determine the short-circuit point with high accuracy.

It is a figure explaining the whole structure of a short circuit monitoring system. 2 is a diagram illustrating a hardware configuration example of a monitoring device 20. FIG. 3 is a diagram illustrating a software configuration example of a monitoring device 20. FIG. It is a figure which shows the structural example of equipment information. It is a figure which shows the specific example of the process which determines whether it is a three-phase short circuit or a single phase short circuit. It is a figure which shows the flow of the orientation process of the short circuit point 5 in the case of a three-phase short circuit. It is a figure which shows the flow of a short circuit distance calculation process. It is a figure which shows an example of the screen 50 which outputs the short circuit point. It is a figure which shows the flow of the orientation process of the short circuit point 5 in the case of a single phase short circuit.

  FIG. 1 is a diagram illustrating the overall configuration of a short-circuit monitoring system according to an embodiment of the present invention. The short-circuit monitoring system according to the present embodiment positions the short-circuit point 5 when a short-circuit accident occurs in the power distribution system 1.

  Power is supplied to the power distribution system 1 from the electric power station 2 through the feeder 3 to the power distribution system 1. The distribution path 4 is a three-phase three-wire system, and includes a first phase line 41, a second phase line 42, and a third phase line 43. A plurality of watt-hour meters (referred to as “smart meters”) 10 with a distribution path communication function are connected to the distribution path 4 via pole transformers 7. The pole transformer 7 includes two single-phase transformers 71 and 72, and is connected to the smart meter 10 by V connection. In order to prevent a three-phase unbalance in the power distribution path 4, the connection configuration between the pole transformer 7 and the power distribution path 4 is different depending on the power pole (not shown). That is, there are three types of combinations of a total of four wires, two wires connected to the single-phase transformer 71 and two wires connected to the single-phase transformer 72, but the same configuration is obtained even in the nearby power pole. In addition, the configuration depending on the utility pole is not regular. For example, in the example of FIG. 1, in SM1, the single-phase transformer 71 is connected to the second phase line 42 at the contact 61, the third phase line 43 is connected at the contact 62, and the single-phase transformer 72 is connected at the contact 63. The first phase wire 41 is connected to the third phase wire 43 by a contact 64, whereas in SM2, the contact 61 of the single-phase transformer 71 is provided on the first phase wire 41, and the single-phase transformer 72 of the contact 63 is provided on the second phase line 42. In this embodiment, in order to simplify the explanation, one smart meter 10 corresponds to one pole transformer 7, and the connection configuration of the single-phase transformer 7 is different for each smart meter 10. .

  The smart meter 10 measures the voltage, current, power factor, and the like supplied from the pole transformer 7 to thereby measure the voltage at the connection point 6 (corresponding to the “measurement point” of the present invention) to the distribution path 4. , Current and power factor can be measured. A monitoring device 20 is connected to each smart meter 10 via a communication path 30. In the present embodiment, the smart meter 10 transmits the measured voltage to the monitoring device 20 every predetermined time (for example, any time such as 30 seconds, 1 minute, 5 minutes, 30 minutes). It shall be. The monitoring device 20 (corresponding to the “short circuit point locating device” of the present invention) detects the occurrence of a short circuit in the distribution path 4, calculates the voltage change rate based on the voltage acquired from the smart meter 10, and calculates it. For example, a computer such as a personal computer, a workstation, a PDA (Personal Digital Assistant), or a mobile phone terminal that locates the short-circuit point 5 according to the voltage change rate.

  When a short circuit occurs in the distribution path 4, a voltage drop due to a short circuit current occurs. When the short circuit of the distribution path is a three-phase short circuit, in the smart meter 10 (SM1, SM2) connected to the power supply side from the short circuit point 5, the closer to the short circuit point 5 (that is, the farther from the feeder 3). ) The voltage drop rate becomes large, and a power failure (that is, the voltage drop rate becomes 100%) occurs in the smart meter 10 (SM3, SM4) connected to the load side from the short circuit point 5. On the other hand, when the short circuit of the distribution line is a single-phase short circuit, the connection configuration between the pole transformer 7 and the distribution line 4 is different for each smart meter 10, so the distance from the feeder 3 and the voltage drop rate No longer correlate. Therefore, in the short-circuit monitoring system according to the present embodiment, when the voltage drop rate increases as the line length from the feeder 3 increases, the three-phase short-circuit, Otherwise, it is determined as a single-phase short circuit, and the distance from the connection point 6 to the short circuit point 5 (hereinafter referred to as “short circuit distance”) is calculated by the percent impedance method based on the voltage drop rate. Point 5 is oriented.

  FIG. 2 is a diagram illustrating a hardware configuration example of the monitoring device 20. The monitoring device 20 includes a CPU 201, a memory 202, a storage device 203, a communication interface 204, an input device 205, and an output device 206. The storage device 203 is, for example, a hard disk drive or a flash memory that stores various data and programs. The CPU 201 implements various functions by reading a program stored in the storage device 203 into the memory 202 and executing it. The communication interface 204 is an interface for connecting to the communication path 30. For example, a PLC (Power Line Communication) adapter for performing data communication on the power line 4, a modem for connecting to a public telephone line network, a mobile phone line A communication device for connecting to a network, an adapter for connecting to Ethernet (registered trademark), a wireless communication device for performing wireless communication, and the like. The input device 205 is, for example, a keyboard, mouse, button, touch panel, microphone, or the like that inputs data. The output device 206 is, for example, a display, a printer, or a speaker that outputs data.

  FIG. 3 is a diagram illustrating a software configuration example of the monitoring device 20. The monitoring device 20 includes a voltage drop rate acquisition unit 211, a short circuit detection unit 212, a short circuit distance calculation unit 213, a short circuit point location unit 214, a short circuit point output unit 215, and an equipment information database 231. The voltage drop rate acquisition unit 211, the short-circuit detection unit 212, the short-circuit distance calculation unit 213, the short-circuit point location unit 214, and the short-circuit point output unit 215 read the program stored in the storage device 203 into the memory 202 and execute it. Is realized. The facility information database 231 is realized as part of a storage area provided by the memory 202 or the storage device 203.

  The facility information database 231 stores information related to the smart meter 10 connected to the power distribution path 4 (hereinafter referred to as “facility information”). FIG. 4 is a diagram illustrating a configuration example of facility information stored in the facility information database 231. The facility information includes meter ID, main line, line length, target point, target point distance, immediately preceding voltage, current voltage, voltage drop rate, and power-off flag. The meter ID is information for identifying the smart meter 10. The trunk line is information for specifying the feeder 3 of the power distribution path 4 to which the smart meter 10 is connected. The track length is the length of the power distribution path 4 from the feeder 3 to the connection point. The target point is a power facility on the power source side relative to the connection point 6 for specifying the position of the connection point 6 where the smart meter 10 is connected to the distribution path 4 (hereinafter, this power facility is referred to as “target point”). The target point distance is a distance from the target point to the connection point 6. In this embodiment, it is assumed that the unit of distance is meters (m). A voltage is periodically transmitted from the smart meter 10, and the current voltage is the voltage received most recently, and the immediately preceding voltage is the voltage received before that. The voltage drop rate is a voltage drop rate from the immediately preceding voltage to the current voltage. The power-off flag is a flag value indicating whether or not the smart meter 10 has a power failure (whether or not a power supply voltage exists). The voltage drop rate and the power-off flag are updated every time a voltage is received from the smart meter 10.

  The voltage drop rate acquisition unit 211 acquires a voltage. In the present embodiment, the voltage drop rate acquisition unit 211 receives the voltage periodically transmitted from the smart meter 10 and is stored in the facility information database 231 and the facility information corresponding to the smart meter 10 that has received the voltage. Is set to the immediately preceding voltage, and the received voltage is set to the present voltage of the facility information, and the voltage drop rate from the immediately preceding voltage to the present voltage is calculated. In addition, the voltage drop rate acquisition part 211 can also acquire the electric current, the power factor, etc. which the smart meter 10 measured together. The voltage drop rate acquisition unit 211 sets the power-off flag to “true” if the voltage drop rate is equal to or higher than a predetermined threshold (for example, a value such as 98% or 100% can be set). If the voltage drop rate is less than a predetermined threshold, the power-off flag is set to “false”.

The short circuit detection unit 212 detects that a short circuit has occurred in the power distribution system 1. The short circuit detection unit 212 detects occurrence of a short circuit by a general method. For example, the short circuit detection unit 212 can detect the occurrence of a short circuit by detecting the operation of a reclose relay (not shown), an overcurrent circuit breaker (not shown), or the like. Further, the short circuit detection unit 212 may detect a short circuit when the voltage drop rate acquired from the smart meter 10 is 100% or when the voltage acquired from the smart meter 10 is 0V. It is assumed that the short circuit detection unit 212 can also identify a trunk line in which a short circuit has occurred.
Moreover, the short circuit detection part 212 determines whether it is a three-phase short circuit or a single phase short circuit. FIG. 5 is a diagram illustrating a specific example of processing for determining whether a three-phase short circuit or a single-phase short circuit. Note that the processing in FIG. 5 is performed only on the trunk line in which a short circuit is detected, but may be performed on each trunk line.
The short circuit detection unit 212 reads the facility information corresponding to the trunk line that has detected the short circuit from the facility information database 231 and sorts the facility information in ascending order of the line length (S301). The short-circuit detecting unit 212 sets the first list of facility information as X1 (S302), and performs the following processing while there is next facility information.
The short circuit detection unit 212 sets the next facility information as X2 (S303), sets the value obtained by subtracting the voltage drop rate of X1 from the voltage drop rate of X2 as ΔVV (S304), and ΔVV is a predetermined threshold value (for example, −0. An arbitrary value such as 5% or -1.0% can be set.) When the value is smaller (S305: YES), that is, when the voltage drop rate decreases more than a certain value even if the line length becomes longer. Is determined as a single-phase short circuit (S306), and the process is terminated.
On the other hand, if ΔVV is not less than the threshold value (S305: NO), the short circuit detection unit 212 sets X2 to X1 (S307) and repeats the processing from step S303.
If ΔVV does not fall below the threshold value for all the read equipment information, the short circuit detection unit 212 determines that the three-phase short circuit has occurred (S308).
As described above, the short-circuit detection unit 212 can determine whether the short-circuit detection unit 212 is a three-phase short circuit or a single-phase short circuit depending on whether the voltage drop rate increases as the line length from the feeder 3 increases.

The short circuit distance calculation unit 213 calculates the short circuit distance based on the voltage drop rate acquired from the smart meter 10.
The short-circuit distance is calculated by the percent impedance method. In addition, regarding the distribution path 4, the resistance r (Ω / km) per unit distance (1 km), the reactance x (Ω / km) per km, the percent resistance% R (%) per km, the percent reactance% per km X (%) is assumed to be known. It is also assumed that the delivery voltage G (V) and the rated current I (A) from the electric station 2 are known.

The percent impedance% Zl (%) from the connection point 6 to the short-circuit point 5 is expressed by the following (1) where the percent resistance is% Rl (%), the percent reactance is% Xl (%), and the short-circuit distance is L (km). -Calculated by equation (3).

The short circuit current Is (A) is calculated by the following equation (4) or (5).

The resistance rl (Ω), reactance xl (Ω) and impedance zl (Ω) from the connection point 6 to the short-circuit point 5 are calculated by the following equations (6) to (8).

The line side voltage drop ΔVl (V) at the short-circuit point 5 is calculated by the following equation (9) or (10).

The voltage change rate ε (%) at the connection point 6 is calculated by the following equation (11).

  The short-circuit distance calculation unit 213 receives input of impedance (back impedance)% Xb (%) on the power supply side, changes the short-circuit distance L, and the voltage change rate ε and the voltage drop rate acquired from the smart meter 10 are obtained. The matching L is calculated.

The short circuit point locating unit 214 positions the short circuit point 5. As described above, when a short circuit occurs in the distribution path 4, a voltage drop due to a short circuit current occurs in the smart meter 10 connected to the power source side from the short circuit point 5, and the voltage drop rate increases as the power source is approached. On the other hand, in the smart meter 10 connected to the load side with respect to the short-circuit point 5, a power interruption occurs. Therefore, in the monitoring device 20 of the present embodiment, among the smart meters 10 connected to the same bank as the smart meter 10 in which the power interruption has occurred, a smart in which no voltage interruption has occurred and the voltage drop rate is the smallest. The short-circuit point 5 is determined using the meter 10 as a reference. In addition, the detail of the orientation process of the short circuit point 5 is mentioned later.
The short-circuit point output unit 215 outputs the short-circuit point 5 determined by the short-circuit point locating unit 213.

FIG. 6 is a diagram illustrating a flow of the orientation process for the short-circuit point 5 in the case of a three-phase short circuit. The process of FIG. 6 is executed when the short circuit detection unit 212 detects a short circuit and determines that the short circuit is a three-phase short circuit.
The short-circuit point location unit 214 corresponds to the trunk line detected by the short-circuit detection unit 212 from the facility information database 231 and acquires the shortest line length among the facility information whose power-off flag is “true”. The shortest power-off facility information is set (S401). The short-circuit point location unit 214 corresponds to the trunk line detected by the short-circuit detection unit 212, the power-off flag is “false”, and the line length is the shortest among the pieces of equipment information whose line length is shorter than the line length of the shortest power-off equipment information. A long one is acquired and used as reference facility information (S402).

The short circuit distance calculation unit 213 calculates the short circuit distance based on the voltage drop rate as shown in FIG. 7 (S403).
As shown in FIG. 7, the short-circuit distance calculation unit 213 receives the input of the back impedance% Xb (S421), sets the short-circuit distance L to 0 (S422), and sets the voltage drop rate of the reference facility information to ΔV (S423). ), A maximum value 100 (%) is set as the voltage change rate ε (S424).
If ΔV is less than ε (S425: YES), the short-circuit distance calculating unit 213 adds a predetermined step value (for example, 0.1) to L (S426), and the above formulas (1) to (3) are added. % Zl is calculated by applying L (S427). The short-circuit distance calculating unit 213 applies% Zl to the above formula (4) or (5) according to the three-phase short circuit or the single-phase short circuit detected by the short circuit detection unit 212, and calculates Is (S428). The short-circuit distance calculation unit 213 calculates zl by applying L to the above equations (6) to (8) (S429), and Is and zl according to the above equation (9) according to the three-phase short circuit or the single-phase short circuit. ) Or (10) to calculate the voltage drop ΔVl (S430), ΔVl is applied to the above equation (11) to calculate ε (S431), and the process returns to step S425.
If ΔV is equal to or greater than ε (S425: NO), the short circuit distance calculation unit 213 ends the process, and the short circuit distance L is determined.
As described above, the short circuit distance is calculated.

Returning to FIG. 6, the short-circuit point location unit 214 calculates the distance from the target point to the short-circuit point (hereinafter referred to as “location distance”) by adding the short-circuit distance L to the target point distance of the reference equipment information ( S404). As a result, the short circuit point locating unit 214 determines the position of the standard distance from the target point to the load side as the short circuit point 5.
The short-circuit point output unit 215 outputs the trunk line, the target point, and the orientation distance of the reference facility information as information for specifying the short-circuit point 5 (S405). FIG. 8 is a diagram illustrating an example of a screen 50 for displaying the short-circuit point 5 output by the short-circuit point output unit 215. The screen 50 includes display columns 51-54. The short-circuit point output unit 215 displays a character string (“short-circuit accident occurrence” in the example of FIG. 8) indicating that the short-circuit detection unit 212 has detected a short circuit in the display field 51. The short-circuit point output unit 215 displays the reference facility information bank in the display column 52, displays the target point of the reference facility information in the display column 53, and displays the orientation distance calculated by the short-circuit point location unit 214 in the display column 54. To do.

FIG. 9 is a diagram illustrating a flow of the orientation process for the short-circuit point 5 in the case of a single-phase short circuit.
The short-circuit point locating unit 214 reads the facility information corresponding to the trunk line detected by the short-circuit detecting unit 212 from the facility information database 231 and sorts the facility information in ascending order of the line length (S441). The short-circuit point location unit 214 sets X1 as the first list in the sorted facility information (S442), and performs the following processing while there is next facility information.
The short-circuit point location unit 214 sets the next facility information as X2 (S443), sets the value obtained by subtracting the voltage drop rate of X1 from the voltage drop rate of X2 as ΔVV (S444), and ΔVV is a predetermined threshold (for example, 50%). It is possible to set an arbitrary value such as 60%.) It is determined whether or not the voltage drop is significant (S445). When it is determined that the voltage drop is significant (S445: NO), the short-circuit point location unit 214 sets X1 as reference facility information (S446).
On the other hand, when it is determined that the voltage drop is not significant (S445: YES), the short-circuit point locating unit 214 sets X2 to X1 (S447) and repeats the processing from step S443. If ΔVV does not exceed the threshold value for all the read facility information, the short-circuit point locating unit 214 sets the first sorted facility information as reference facility information (S448).
The short-circuit point location unit 214 calculates the short-circuit distance based on the voltage drop rate by the process of FIG. 7 described above (S449). The short-circuit point location unit 214 adds the short-circuit distance L to the target point distance of the reference facility information, calculates the orientation distance, and locates the location of the orientation distance from the target point to the load side as the short-circuit point 5 (S450). . The short-circuit point output unit 215 outputs the trunk line, the target point, and the orientation distance of the reference facility information as information for specifying the short-circuit point 5 on the screen 50 as shown in FIG. 8 (S451).
As described above, the short-circuit point locating unit 214 can calculate the short-circuit distance based on the voltage drop rate according to the three-phase short circuit or the single-phase short circuit, and thereby can determine the short-circuit point 5.

  As described above, according to the short-circuit monitoring system of the present embodiment, the short-circuit point location unit 214 has the formula (4) or (5) or the formula (9) or ( 10) can be used to calculate the short circuit distance. Therefore, since an appropriate formula can be used according to the type of short circuit, the short circuit distance can be calculated with high accuracy.

  Further, according to the short circuit monitoring system of the present embodiment, in the case of a three-phase short circuit, the short circuit distance can be calculated based on the voltage drop rate at the location closest to the upstream from the location where the power failure occurred. In the case of a three-phase short circuit, it is conceivable that the short circuit point 5 exists near the location where the power failure occurs, so that the short circuit distance can be calculated with high accuracy. On the other hand, in the case of a single-phase short-circuit, the short-circuit distance can be calculated based on the voltage drop rate at the location closest to the power transmission source (feeder 3) among the places where the voltage drop is significantly generated. In the case of a single-phase short-circuit, the voltage drop rate varies depending on the connection configuration of the pole transformer 7, and even if the short circuit is not generated in the distribution path 4, a voltage drop occurs in the downstream and the voltage drop rate is accurate. Since the value does not become a value, the short-circuit distance can be calculated with higher accuracy by calculating the short-circuit distance on the basis of the upstream location among locations where a significant voltage drop has occurred.

  Moreover, in the short circuit monitoring system of this embodiment, the short circuit point 5 can be output as a target point and the orientation distance from there. Therefore, the worker for the short circuit repair can easily specify the repair location with reference to the output from the monitoring device 20.

  Further, in the short circuit monitoring system of the present embodiment, the short circuit distance and the orientation distance are calculated for only one reference smart meter 10. Therefore, it is not necessary to calculate all of the large number of smart meters 10, and the short-circuit point 5 can be quickly determined. Therefore, it becomes possible to repair the short-circuit point 5 at an early stage.

  In the present embodiment, it is assumed that all pole transformers 7 are composed of two single-phase transformers 71 and 72. However, for example, from three single-phase transformers or one three-phase transformer. The case where the pole transformer 7 comprised is also considered. In this case, the monitoring device 20 stores the configuration of the pole transformer 7 connected to each smart meter 10 and corresponds to the pole transformer 7 including the two single-phase transformers 71 and 72. Only the smart meter 10 can be processed as described above.

  In the present embodiment, the smart meter 10 transmits the measured voltage to the monitoring device 20, and the monitoring device 20 calculates the voltage drop rate. However, the present invention is not limited to this, and the smart meter 10 measures the voltage measured. The voltage change rate in a predetermined period can be measured. In this case, for example, the voltage drop rate acquisition unit 211 transmits a command for acquiring the voltage drop rate and the voltage to the smart meter 10 and receives the voltage drop rate and the voltage responded from the smart meter 10 in response to the command. The smart meter 10 may measure the voltage every predetermined time, calculate a voltage drop rate based on the measured voltage, and automatically calculate the calculated voltage drop rate and the measured voltage. You may make it transmit to the monitoring apparatus 20. FIG.

  Further, the voltage drop rate acquisition unit 211 may periodically acquire the voltage drop rate from each smart meter 10 only when the short circuit detection unit 212 detects a short circuit.

  In the present embodiment, the facility information database 231 stores the facility information for each smart meter 10, but the facility information may be stored for each connection point 6.

In the present embodiment, the smart meter 10 measures the voltage drop rate at the connection point 6, but a lead-in line from the connection point 6 to the smart meter 10 may be considered. in this case,
The distance from the installation point of the smart meter 10 to the connection point 6 is registered in the facility information, and is subtracted from the short-circuit distance.

  In this embodiment, the percent resistance% Rl and the percent reactance% Xl are calculated based on the percent resistance% R and the percent reactance% X per km. However, the line for each section constituting the distribution path 4 is used. You may make it calculate based on% R and% X according to a seed | species. In this case, the monitoring device 20 includes a distribution line information storage unit that stores% R and% X for each line type of the distribution line, and a line configuring each section from the feeder 3 to the smart meter 10 for each smart meter 10. A short circuit distance calculation unit 213 reads the line type corresponding to the smart meter 10 and the distance from the distribution path configuration storage unit, and reads the line type and the distance thereof. % R and% X corresponding to the line type are read from the distribution line information storage unit, and instead of the above formula (1), the value obtained by multiplying the distance by% R for each line type is calculated to calculate% Rl. Instead of the formula (2), the value obtained by multiplying the distance by% X for each line type is summed to calculate% Xl. Thereby, the short-circuit distance can be calculated with higher accuracy.

  Moreover, in this embodiment, in the orientation process of FIG. 6, only one reference | standard equipment information was acquired and the short circuit point 5 was standardized based on the reference | standard equipment information. The unit 214 calculates the short-circuit distance by the short-circuit distance calculation unit 213 for each of a predetermined number of pieces of facility information in order of the line length from the reference facility, and the short-circuit point location unit 214 calculates the orientation distance and outputs this short-circuit point output. The unit 215 may output the data. Further, the orientation distance may be converted into a distance from the feeder 3, and the average of the converted distances may be used as the orientation distance. Furthermore, the target points included in the predetermined number of pieces of equipment information are identified most frequently, and among the predetermined number of pieces of equipment information, only those that include the specified target points are calculated and output. Also good.

  Although the present embodiment has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Distribution system 2 Electricity station 3 Feeder 4 Distribution path 5 Short-circuit point 6 Connection point 7 Pillar transformer 71 Single phase transformer 72 Single phase transformer 73 Three phase transformer 10 Smart meter 20 Monitoring apparatus 30 Communication path 201 CPU
202 Memory 203 Storage Device 204 Communication Interface 205 Input Device 206 Output Device 211 Voltage Drop Rate Acquisition Unit 212 Short Circuit Detection Unit 214 Short Circuit Point Location Unit 215 Short Circuit Point Output Unit 231 Facility Information Database

Claims (9)

A device for locating a short-circuit point in a three-phase three-wire distribution line,
The distribution path is composed of two single-phase transformers, and a plurality of transformers having different combinations of four wires to which the two single-phase transformers are connected are connected.
A voltage drop rate acquisition unit for acquiring a voltage drop rate at each of the connection points of the transformer to the distribution path;
A short-circuit type determination unit that determines whether a three-phase short circuit or a single-phase short circuit is based on whether the drop rate is large as the line length from the feeder that supplies power to the distribution path is long.
A short-circuit distance calculation unit that calculates a distance from the connection point to the short-circuit point based on the drop rate, depending on whether a three-phase short circuit or a single-phase short circuit,
A short-circuit point locating device comprising: The short-circuit point location device according to claim 1 ,
Further comprising a power failure determination unit for determining whether a power failure has occurred at the connection point based on the rate of descent,
The short-circuit distance calculation unit, when it is determined as a three-phase short-circuit, to calculate only the distance from the connection point closest to the connection point where a power failure has occurred, and the connection point where a power failure has not occurred,
A short-circuit point locator characterized by The short-circuit point locating device according to claim 1 or 2 ,
When the short-circuit distance calculation unit determines that the single-phase short-circuit, the descent rate for the first connection point among the first connection points that are the connection points, and the first connection point The difference between the second connection point of the line length that is the next longest and the drop rate exceeds a predetermined threshold value, and the short circuit from the connection point only for the specified first connection point Calculating the distance to a point;
A short-circuit point locator characterized by The short-circuit point locating device according to any one of claims 1 to 3 ,
Connected to the transformer, communicably connected to a voltage measuring device for measuring the voltage output from the transformer,
The voltage drop rate acquisition unit acquires the voltage from the voltage measurement device, and calculates the drop rate based on the acquired voltage;
A short-circuit point locator characterized by The short-circuit point locating device according to any one of claims 1 to 3 ,
Connected to the transformer, communicatively connected to a voltage measuring device for measuring the drop rate,
The voltage drop rate acquisition unit acquires the drop rate from the voltage measuring device;
A short-circuit point locator characterized by The short-circuit point locating device according to claim 4 or 5 ,
The voltage measuring device is a watt-hour meter having a communication function;
A short-circuit point locator characterized by The short-circuit point locating device according to any one of claims 1 to 6 ,
For each connection point, a facility information storage unit that stores a target point in the distribution path and a target point distance that is a distance from the target point to the connection point;
The target point corresponding to the connection point and the target point distance are read from the facility information storage unit, a standardization distance that is a distance obtained by adding the distance to the read target point distance is calculated, and the standardization is calculated from the target point A short-circuit point locating unit that standardizes a distance point as the short-circuit point;
A short-circuit point locating device further comprising: A method of locating a short-circuit point in a three-phase three-wire distribution line,
The distribution path is composed of two single-phase transformers, and a plurality of transformers having different combinations of four wires to which the two single-phase transformers are connected are connected.
Computer
Obtaining a voltage drop rate at each of the connection points of the transformer to the distribution path;
Whether the drop rate is large as the line length from the feeder that supplies power to the distribution line is long, determines whether a three-phase short circuit or a single-phase short circuit,
Depending on whether a three-phase short circuit or a single-phase short circuit, calculating the distance from the connection point to the short circuit point based on the drop rate,
A short-circuit location method characterized by: A program for locating a short-circuit point in a three-phase three-wire distribution line,
The distribution path is composed of two single-phase transformers, and a plurality of transformers having different combinations of four wires to which the two single-phase transformers are connected are connected.
On the computer,
Obtaining a voltage drop rate at each of the connection points of the transformer to the distribution path;
Whether the three-phase short circuit or the single-phase short circuit is determined depending on whether the drop rate is large as the line length from the feeder that supplies power to the distribution path is long.
Calculating a distance from the connection point to the short-circuit point based on the drop rate, depending on whether a three-phase short circuit or a single-phase short circuit;
A program for running

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