JPH04331417A - System for detecting fault section of distribution line - Google Patents

Abstract

PURPOSE:To know a faulty section of a distribution line with less number of voltage sensors than before by utilizing, in a terminal station, a line voltage between the specified two phases of the distribution line, an ac supply voltage for control of the terminal station. CONSTITUTION:A terminal station T1 detects an earth current of one direction and a terminal station T2 detects an earth current of the opposite direction. Here, an element which has a phase common to the terminal stations T1 and T2, for example, a line voltage between the specified two phases or a phase voltage of the specified one phase is taken and a relative phase difference between the said element and a zero-phase current is calculated and then the result is sent to a master station. Based on a distribution of a phase difference from the zero-phase current, one of the data received from each terminal station, the master station distinguishes a group of the terminal stations which detect a grounded point in the direction there is an sending end, from the other terminal stations. The sections between the adjacent terminal stations out of the distinguished terminal stations are judged as grounded sections of distribution line.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention detects directional ground fault information, short circuit information, and disconnection information by measuring the voltage and current of the distribution line at terminal stations installed in certain sections on the distribution line. The present invention relates to a fault section detection system for power distribution lines that can detect fault sections.

0002

2. Description of the Related Art A power distribution line is an electric line installed between a substation and a consumer, and a large number of power distribution lines are supplied from one substation. In addition to circuit breakers, each distribution line is provided with section switches at regular intervals. When an accident such as a ground fault occurs in the middle of a distribution line, the circuit breaker is opened, and the sectional switch is also opened accordingly to protect the distribution line. It is important to detect where the faulty section is in order to supply power to the system.

[0003] Therefore, in the past, terminal stations (which may be installed at the same location as the section switches or at a different location) are installed at regular intervals along the distribution line. ). This terminal station is
It has three current sensors that measure each phase current and three voltage sensors that measure each phase voltage. Short circuit and disconnection information is determined at the terminal station, and zero-sequence current I is detected from the three current sensors.
0, and calculate the zero-sequence voltage V0 from the three voltage sensors. The ground fault information and directional ground fault information are determined in the terminal station and sent to the master station, and the master station calculates the terminal station that detected the fault in the direction where the substation is located and the direction where the load is located. The section located between the terminal station and the terminal station where the failure was detected was considered to be the failed section.

0004

[Problem to be Solved by the Invention] The terminal station described above requires three voltage sensors, but these voltage sensors are required to be attached directly to the normally installed power distribution line and optically measure the voltage between them and the ground. A type of measurement is used. However, since we are measuring high voltage (e.g. 6.6kV),
The drawback is that it is greatly affected by the insulation resistance with the ground. For example, if the insulation resistance with the ground changes due to weather or dirt on the surface of the voltage sensor, the phase angle of the measured voltage may deviate from the phase angle of the actual voltage, or an error may occur in the magnitude of the measured voltage itself.

[0005] Therefore, if the voltage sensor is constituted by a transformer PT and built into the terminal station, the above-mentioned drawbacks will not occur, but in order to detect the zero-sequence voltage V0, three expensive transformers PT must be installed. There's a problem. A large number of terminal stations are placed on each distribution line, and considering the large number of distribution lines, it is preferable to make the configuration of the terminal station as simple as possible.
It is better to keep the number as small as possible.

[0006] An object of the present invention is to solve the above-mentioned technical problems, and to provide a distribution line in which faulty sections of the distribution line can be known by arranging terminal stations that use a smaller number of voltage sensors than in the past. The object of the present invention is to provide a fault section detection system.

[0007]

[Means for Solving the Problems] A distribution line failure section detection system according to claim 1 for achieving the above object,
A terminal station is placed in each section of a distribution line divided into multiple sections, a master station is placed to receive data from the terminal station, and each terminal station has a current that detects each phase current of the distribution line. A short circuit or a disconnection in the distribution line is determined by comparing the line voltage between two predetermined phases of the distribution line, which is the current detected by the sensor and the current sensor, and the control AC power supply voltage of the terminal station, with respective reference values. The short circuit/disconnection determination means determines the zero-sequence current based on the detected current of the current sensor, and determines the position of the zero-sequence current and the line voltage between two predetermined phases of the distribution line, which is the control AC power supply voltage of the terminal station. A calculation means for calculating a phase difference, and a transmission means for transmitting data on the phase difference detected by the calculation means and short circuit or disconnection data determined by the determination means are provided, and the master station receives data from each terminal station. Based on the distribution of the phase difference included in the received data, groups of terminal stations having a phase difference of approximately 180° are distinguished, and sections existing between terminal stations adjacent to each other among these distinguished groups of terminal stations are distinguished. a ground fault fault section determination means for determining a ground fault fault section of a distribution line; and a short circuit fault section for determining a short circuit fault section or a break fault section based on a short circuit or disconnection determination result included in data received from each terminal station. Disconnection failure section determining means is provided.

[0008] A faulty section detection system for a distribution line according to claim 2 for achieving the above object includes a terminal station arranged in each section of a distribution line divided into a plurality of sections, and a system for detecting data from the terminal station. Each terminal station has a voltage sensor that detects the phase voltage of one predetermined phase of the distribution line, a current sensor that detects the current of each phase of the distribution line, and A short-circuit-and-disconnection determination means for determining whether a distribution line is short-circuited or disconnected by comparing each phase current and the phase voltage of the predetermined one phase with a reference value, and a zero-sequence current is determined based on the current detected by the current sensor. , a calculation means for calculating a phase difference between the zero-phase current and a predetermined one-phase phase voltage detected by a voltage sensor, and data on the phase difference detected by the calculation means and a short circuit or a short circuit determined by the determination means. A transmitting means for transmitting disconnection data is provided, and the master station distinguishes between a group of terminal stations having a phase difference of approximately 180° based on the distribution of the phase difference included in the data received from each terminal station. and ground fault fault section determination means for determining a section existing between adjacent terminal stations among these differentiated terminal stations as a ground fault fault section of the distribution line; A short-circuit/disconnection fault section determining means is provided for determining a short-circuit/disconnection fault section or a breakage section based on the determination result of the included short circuit or disconnection.

A faulty section detection system for a distribution line according to claim 3 is one in which the short circuit/disconnection determination means according to claim 1 is provided on the side of a master station, and a faulty section detection system for a distribution line according to claim 4 is provided with , the short circuit/disconnection determining means of claim 2 is provided on the master station side.

0010

[Operation] According to each of the above-mentioned inventions, when a distribution line is short-circuited or disconnected, each phase current of the distribution line and the line voltage between the predetermined two phases or the phase voltage of the predetermined one phase are compared with a reference value. By doing so, it is possible to determine whether the distribution line is short-circuited or disconnected at each terminal station, and determine the short-circuit failure section or the disconnection failure section based on the determination result.

Furthermore, when a distribution line has a ground fault, if the phase difference between the zero-sequence current and the line voltage between two predetermined phases or the phase voltage of one predetermined phase is θ, then the ground fault fault point and the terminal station By utilizing the fact that the phase difference θ is reversed by about 180 degrees depending on the positional relationship between the It is possible to distinguish between a group of terminal stations in which a connection point is detected, and to determine a section located between mutually adjacent terminal stations among these distinguished terminal stations as a ground fault section of the power distribution line.

[0012] This will be explained in detail. FIG. 1 is a conceptual diagram of a power distribution line, and assumes that power sources Ea, Eb, and Ec exist at the power transmission end. Terminal stations installed adjacent to each other are indicated as T1 and T2. Assume that a ground fault occurs between terminal stations T1 and T2, and that the ground fault resistance is Rg. C1 and C2 are
These are the ground capacity of the distribution line on the power supply side and load side of the ground fault point, respectively.

[0013] When a ground fault occurs, the zero-sequence voltage V0 at the ground fault point is expressed as V0 = -Ea/(1+3jωCRg). Here, C=C1 +C2. Furthermore, the zero-sequence current I0 detected at the terminal station T1 is I0 = C1 Ig/3C
(1
) What is detected at terminal station T2 is I0 = -C2 Ig/3C
(2)
It is. Here, Ig=3jωCEa/(1+3jωCRg).

From equations (1) and (2) above, it can be seen that terminal station T1 and terminal station T2 detect ground fault currents in opposite directions. Therefore, an element having a common phase between the terminal station T1 and the terminal station T2, for example, the line voltage between two predetermined phases or the phase voltage of one predetermined phase, is taken and the relative phase difference between it and the zero-sequence current is calculated. , to the master station, the master station detects a ground fault in the direction of the power transmission end based on the distribution of the phase difference with the zero-sequence current included in the data received from each terminal station. It is possible to distinguish between a terminal station group that detects a ground fault point and a terminal station group that detects a ground fault point in the direction opposite to the direction in which the power transmission end exists. The section where the ground fault occurs can be determined as the section where the distribution line has a ground fault.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will be explained in detail below with reference to the accompanying drawings showing examples. FIG. 2 is a power distribution system diagram, and the distribution substation 1 is equipped with a transformer 11 with a Δ-Δ connection.
1, the power stepped down to 6.6kV is transferred to circuit breakers 3a and 3.
It is supplied to the distribution lines 4a, 4b, . . . through b, . The distribution lines 4a, 4b, . . . are equipped with Y-Y connected transformers 5a1 for distributing power to consumers.
, 5a2, ..., 5b1, 5b2, ... are connected, and terminal stations 7a1, 7a2, ..., 7b1, 7b2, ... are connected near each transformer 5a1, 5a2, ...・・・
・ is provided.

Each terminal station 7a1, 7a2, . . . has the same configuration, and CT1, CT for detecting the current of each phase
2, each phase current information taken out from CT3 and the line voltage information between the ab phases taken out from the transformers 5a1, 5a2, etc. (this line voltage between the ab phases is used for the driving power source of the terminal station) It is not necessary to install a new voltage sensor). An arithmetic processing unit 71 that calculates the phase difference θ, etc. and determines whether there is a ground fault, short circuit, or disconnection, and the judgment result obtained by the arithmetic processing unit 71 is converted into 4-bit data and transmitted to the master station 9 (see FIG. 8). The transmitter 72 is provided with a transmitter 72 for transmitting data.

As shown in FIG. 3, the arithmetic processing section 71 includes an addition circuit 716 that calculates the value of the zero-phase current, and an addition circuit 716 that calculates the value of the a-phase current Ia.
A sample hold circuit 711 that samples the value of
, a sample-and-hold circuit 712 that samples the value of the b-phase current Ib, a sample-and-hold circuit 713 that samples the value of the c-phase current Ic, and a sample-and-hold circuit 7 that samples the value of the zero-sequence current I0.
14 and a sample hold circuit 715 that samples the value of the line voltage Vab, a multiplexer 720 that sends out the sampled and held values in chronological order, and a conversion circuit that A/D converts the data output from the multiplexer 720. Circuit 730 and A/D
The converted data is digitally calculated to calculate the line voltage Vab.
, the magnitude and phase angle of each phase current Ia, Ib, Ic, zero-sequence current I0, positive-sequence current I1, negative-sequence current I2, and the phase difference θ between line voltage Vab and zero-sequence current I0, Negative sequence current I2 relative to the magnitude of positive sequence current I1
Calculation circuit 74 that calculates the ratio I2/I1 of the size of
0 and a determination circuit 750 that determines whether there is a ground fault, short circuit, or disconnection based on the calculation data of the calculation circuit 740.

Furthermore, the arithmetic processing unit 71 calculates the line voltage Va
A fundamental wave pulse generation circuit 760 that generates a fundamental wave pulse every cycle of b, and a frequency divider 7 that divides the frequency of the pulse thus generated by a predetermined frequency division ratio (for example, 1/12 times).
61, and a finer frequency division ratio (for example, 1/6
A frequency divider 762 that divides the frequency by
switching controller 76 providing switching control signals to 715;
3, and the calculation circuit 740 performs calculation processing using the output pulse of the frequency divider 761 as a synchronization signal.

The calculation circuit 740 can use any conventionally known method to calculate the magnitude and phase angle of the current or voltage. For example, the magnitude can be determined by determining a Fourier sine component and a Fourier cosine component over one period and taking the root mean of both components. Further, the phase angle can be determined by taking the ratio tan-1 of the Fourier sine component and the Fourier cosine component.

FIG. 4 is a flowchart showing the procedure for determining ground faults, short circuits, and disconnections performed by the determination circuit 750. Figure 4
According to , the determination circuit 750 performs a short circuit determination (step (1)) based on various data supplied from the calculation circuit 740 , and if it is determined that there is a short circuit, it sends a code "0001" representing a short circuit to the transmitter 72 . Send to. If it is determined that there is no short circuit, a disconnection determination (step (2)) is performed.
If it is determined that the wire is broken, a code "0010" representing the wire breakage is sent.

If it is determined that there is no disconnection, it is determined that there is a ground fault (
Perform steps (3) (4)). Step (3)
Now, the zero-sequence current I0 is compared with the threshold value Ix, and the zero-sequence current
If I0 exceeds the threshold Ix, step (4)
, the phase difference θ between the line voltage Vab and the zero-sequence current I0 is in the regions I, II, . . ., which equally divides 360° into 8 regions.
VIII (see FIG. 5), and sends out the corresponding code in step (7). For example, if 0<θ≦π/4, it falls into region I, so the code “10
00" is transmitted. If π/4<θ≦π/2, it falls into region II, so the code "1001" is transmitted.
The ground fault determination in steps (3) and (4) means determining a 1-wire ground fault, and in the case of a 2-wire or 3-wire ground fault, it can be determined by the short circuit determination in step (1). (3) (4) There is no way to determine a 2-wire ground fault or a 3-wire ground fault.

[0022] If it is determined that there is no ground fault, step (8)
The code "0000" indicating no failure is sent out. The transmitter 72 transmits the code received from the determination circuit 750 to the master station 9 through a medium such as wireless, optical, or infrared rays.
Step (9)). The master station 9 consists of a receiving section 91 and a failure section determining section 92, as shown in FIG.

The short circuit determination in step (1) is shown in FIG.
As shown in FIG. 2, the determination is made based on whether any of the phase currents Ia, Ib, and Ic exceeds a reference current (for example, 1.2 times the rated current). In Figure 6, the reference current is 480A
(The rated current is 400A). Step (2
) As shown in Figure 7, the disconnection determination is made separately for 1-wire disconnection, 2-wire disconnection, and 3-wire disconnection, and when any type of disconnection occurs, it is determined as ``disconnection.'' .

One wire breakage occurs when any of the phase currents Ia, Ib, and Ic exceeds 1% of the rated current, the line voltage Vab exceeds approximately 80% of the phase voltage, and the positive-sequence current I1 and the negative-sequence current I2
The determination is made when the ratio I2/I1 of the magnitude exceeds 0.6 times. In Figure 7, "1% of rated current" is 4A
, about 80% of the "phase voltage" is displayed at 3000V. The number 0.6 times is determined empirically.

Two-wire disconnection occurs when the phase currents Ia, Ib, and Ic are all less than 1% of the rated current, and the line voltage Va
b is determined when it falls within a range of about 1% to about 2.5% of the phase voltage. 3-wire disconnection is caused by each phase current Ia, Ib,
It is determined that Ic is all less than 0.1% of the rated current and the line voltage Vab is less than about 1% of the phase voltage.

The failure section determining section 92 of the master station 9 determines in which section there is a ground fault, short circuit, or disconnection based on the code received from the transmitting section 72 of each terminal through a medium such as radio, light, or infrared rays. do. The method for this determination is as follows. Terminal station 7 along the distribution line as shown in Figure 9.
Assume that a1, . . . , 7a6 are arranged.

When a one-line ground fault occurs between the terminal station 7a3 and the terminal station 7a4 (see FIG. 9(a)), the power is sent from the terminal stations 7a1, 7a2, and 7a3 on the power transmission side from the ground fault point. The regions showing the phase difference θ between the line voltage Vab and the zero-sequence current I0 are the same region or two regions adjacent to each other (for example, regions I and VIII in FIG. 5). However, terminal stations 7a4, 7a5, on the load side from the ground fault point
Line voltage Vab and zero-sequence current I0 sent from 7a6
The region showing a phase difference θ with
These are the regions (regions V and IV in FIG. 5) that are shifted by degrees. Therefore, the master station 9 knows that a ground fault has occurred between the terminal station 7a3 and the terminal station 7a4 before and after the region of phase difference deviates greatly. Since the omnidirectional region is divided into eight regions in this way, the transmission line between the terminal station and the master station only needs to send data indicating which of these eight regions the phase angle falls within. Therefore, there is no need to send phase angle data as is, and an increase in the capacity of the transmission line can be prevented. Also, if the capacity of the transmission line is fixed,
You can increase the capacity to allocate other data.

Next, when a short-circuit failure occurs between the terminal stations 7a3 and 7a4 (see FIG. 9(b)), the power is sent from the terminal stations 7a1, 7a2, and 7a3 on the power transmission side from the failure point. The information sent from terminal stations 7a4, 7a5, and 7a6 located on the load side of the failure point is "short circuit" information, whereas the information sent from the terminal stations 7a4, 7a5, and 7a6 located on the load side from the failure point is "broken wire" information (in the case of a two-wire short circuit) or "failure" information. "None" (in case of 3-wire short circuit). Therefore, the master station 9 is connected to the terminal station 7a3 and the terminal station 7a.
It becomes clear that a short-circuit failure has occurred between the two.

Next, when a disconnection fault occurs between the terminal station 7a3 and the terminal station 7a4 (see FIG. 9(c)), the power is sent from the terminal stations 7a1, 7a2, and 7a3 on the power transmission side from the fault point. The information coming from the terminal station 7a4, 7a5, 7 located on the load side from the failure point is "no failure" information.
The information sent from a6 is "disconnection" information. Therefore, the master station 9 knows that a disconnection fault has occurred between the terminal station 7a3 and the terminal station 7a4.

Although the present invention has been described above based on examples, the present invention is not limited to the above-mentioned examples. In the embodiment described above, the line voltage Vab between the ab and phase was used, but a single phase voltage (for example, the a phase voltage Va) may be used. In this case, since the existing voltage sensor cannot be used, it is necessary to provide one dedicated voltage sensor, but there is an advantage that the configuration is simpler than the conventional one, which required three.

In addition to the circuit shown in FIG. 7, it is also possible to use a circuit as shown in FIG. 10 as the circuit for determining whether one wire is disconnected. In the circuit of FIG. 10, each phase current Ia, I
The determination is made when either b or Ic is less than 1% of the rated current and the line voltage Vab exceeds about 80% of the phase voltage. It is also possible to use the circuit of FIG. Figure 1
In circuit 1, one of the phase currents Ia, Ib, and Ic is less than 1% of the rated current, and the remaining two are 1% or more of the rated current, and
The line voltage Vab exceeds approximately 80% of the phase voltage, and the positive sequence current I
1 and the magnitude of the negative sequence current I2, I2/I1, is 0.
．． Judgment will be made when it exceeds 6 times. If the circuit shown in FIG. 11 is used, if a short-circuit failure occurs, all information sent from terminal stations located on the load side of the failure point will be "no failure" information.

Also, according to FIG. 5, all directions are divided into eight regions, but it is practical if the omnidirectional is divided into at least five regions (if divided into four regions, As shown in Figure 2, the phase angle data occupies the entire area, making it impossible to identify the ground fault section). Various other changes can be made without departing from the gist of the invention.

[0033]

As described above, according to the invention of the failure section detection system for a distribution line as set forth in claim 1, each phase current and the line voltage between two predetermined phases can be detected at the terminal station of each section of the distribution line. It is possible to detect information on short circuits and ground faults in distribution lines using this method, and also to detect a phase difference with a zero-sequence current based on the phase of line voltage between two predetermined phases. The master station can detect the ground fault section from the distribution of the phase difference along each measurement point. In these cases, the terminal station uses the line voltage between two predetermined phases of the distribution line, which is the control AC power supply voltage of the terminal station, so compared to the conventional method of measuring three-wire voltage. This simplifies the configuration of the terminal station and reduces costs, which is particularly advantageous when a large number of terminal stations are arranged.

[0034] According to the invention of the fault section detection system for a distribution line as set forth in claim 2, at the terminal station of each section of the distribution line, each phase current and a predetermined phase voltage of one phase are used to detect short circuits and Not only can ground fault information be detected, but also a phase difference with a zero-sequence current can be detected using the phase of a predetermined one-phase phase voltage as a reference. The master station can detect the ground fault section from the distribution of the phase difference over each measurement point. In these cases, the terminal station only needs to measure one phase voltage, which simplifies the configuration of the terminal station compared to the conventional method of measuring 3-wire voltage.
Furthermore, the cost can be reduced, which is particularly advantageous when a large number of terminal stations are arranged.

According to the invention of the fault section detection system for a distribution line as set forth in claim 3, each terminal station detects each phase current, the line voltage between two predetermined phases, and the phase difference between the zero-sequence current and the line voltage. By detecting and transmitting the data to the master station, the master station can determine ground faults, short circuits, and disconnection fault sections of the distribution line based on the distribution of data sent from each terminal station. . In this case, since the line-to-line voltage between two predetermined phases of the distribution line, which is the control AC power supply voltage of the terminal station, is used, the terminal station The configuration becomes easier and costs can be lowered.
This is particularly advantageous when a large number of terminal stations are arranged.

[0036] According to the invention of the fault section detection system for a distribution line as set forth in claim 4, each terminal station detects each phase current, the phase voltage of a predetermined one phase, and the phase difference between the zero-sequence current and the phase voltage. By transmitting the data to the master station, the master station can determine ground faults, short circuits, and disconnection failure sections of the power distribution line based on the distribution of data sent from each terminal station. In this case, the terminal station only needs to measure one phase voltage, which simplifies the configuration of the terminal station and reduces costs compared to the conventional method of measuring three-wire voltage. This is especially advantageous when a large number of terminal stations are installed.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a power distribution line in which a ground fault has occurred, for explaining the principle of the present invention.

FIG. 2 is a power distribution system diagram in which terminal stations are arranged.

FIG. 3 is a block diagram showing the internal configuration of an arithmetic processing unit provided in the terminal station.

FIG. 4 is a flowchart showing the procedure for determining ground faults, short circuits, and disconnections performed by the determination circuit 750.

FIG. 5 is a diagram in which all directions are divided into eight regions for classifying phase angles.

FIG. 6 is a logic circuit diagram for determining a short circuit.

FIG. 7 is a logic circuit diagram for determining disconnection.

FIG. 8 is a block diagram showing the main part configuration of a master station.

FIG. 9 is a distribution line diagram for explaining a method for determining a fault section of a distribution line.

FIG. 10 is a logic circuit diagram showing another embodiment that performs one-line disconnection determination.

FIG. 11 is a logic circuit diagram showing still another embodiment for determining one-line disconnection.

FIG. 12 is a diagram in which all directions are divided into four regions.

[Explanation of symbols]

4a, 4b Distribution lines 7a1, 7a2, 7b1, 7b1 Terminal station 72 Transmitter 740 Calculation circuit 9 Master station 92 Failure area determination unit I to VIII Regions CT1, CT2, CT3 Current sensors T1, T2
terminal station

Claims (4)

[Claims] Claim 1: A fault section detection system for a distribution line that detects a fault section when a fault occurs in a distribution line, wherein a terminal station is placed in each section of a distribution line divided into multiple sections, and each terminal The station is equipped with a current sensor that detects each phase current of the distribution line, and a line voltage between two predetermined phases of the distribution line, which is the detection current of the current sensor and the control AC power supply voltage of the terminal station, respectively, as a reference value. A short-circuit-disconnection determining means determines whether a distribution line is short-circuited or disconnected by comparing the zero-sequence current based on the current detected by the current sensor, and the zero-sequence current and the control AC power supply voltage of the terminal station. Calculating means for calculating the phase difference between two predetermined phases of the distribution line and the line voltage; and transmitting means for transmitting data on the phase difference detected by the calculating means and data on short circuit or disconnection determined by the determining means. Further, a master station for receiving data from the terminal station is arranged, and the master station has a position control function based on the distribution of the phase difference included in the data received from each terminal station. Ground fault fault section determination means for distinguishing between terminal station groups having a phase difference of approximately 180°, and determining a section existing between mutually adjacent terminal stations among these differentiated terminal station groups as a ground fault fault section of a power distribution line. and short circuit/disconnection fault section determining means for determining a short circuit/disconnection fault section based on a determination result of a short circuit or a discontinuity included in the data received from each terminal station. Fault section detection system for electric wires. Claim 2: A fault section detection system for a distribution line that detects a fault section when a fault occurs in a distribution line, wherein a terminal station is placed in each section of a distribution line divided into multiple sections, and each terminal The station includes a voltage sensor that detects the phase voltage of a predetermined one phase of the distribution line, a current sensor that detects each phase current of the distribution line, and a current sensor that detects each phase current of the distribution line and the phase voltage of the predetermined one phase. A short-circuit/disconnection determination means for determining whether a distribution line is short-circuited or disconnected by comparing each with a reference value, and a zero-sequence current determined based on a current detected by a current sensor, and a predetermined value detected by the zero-sequence current and voltage sensor. A calculation means for calculating a phase difference with the phase voltage of one phase, and a transmission means for transmitting data of the phase difference detected by the calculation means and data of a short circuit or disconnection determined by the determination means, Furthermore, a master station for receiving data from the terminal stations is arranged, and the master station has a phase difference of approximately 180° based on the distribution of the phase differences included in the data received from each terminal station. Ground fault fault section determining means for distinguishing between different terminal station groups and determining a section existing between mutually adjacent terminal stations among the differentiated terminal station groups as a ground fault fault section of the distribution line;
A distribution line characterized in that it is provided with short-circuit-disconnection-failure section determination means for determining a short-circuit failure section or a disconnection-failure section based on a determination result of a short-circuit or disconnection included in data received from each terminal station. Fault section detection system. Claim 3: A fault section detection system for a distribution line that detects a fault section when a fault occurs in a distribution line, wherein a terminal station is placed in each section of a distribution line divided into multiple sections, and each terminal The station has a current sensor that detects each phase current of the distribution line, and calculates the zero-sequence current based on the current detected by the current sensor, and calculates the zero-sequence current and the control AC power voltage of the distribution line for the terminal station. Calculating means for calculating a phase difference between a line voltage between two predetermined phases, data on the phase difference detected by the calculating means, data on each phase current of a distribution line, and data on a line voltage between the predetermined two phases. A transmitting means for transmitting data is provided, and a master station for receiving data from the terminal station is further arranged, and the master station has a transmission means for transmitting data from the terminal station. Based on this, the phase difference is approximately 180
° A ground fault fault section determining means for distinguishing between different terminal station groups and determining a section existing between mutually adjacent terminal stations among the differentiated terminal station groups as a ground fault fault section of the distribution line, and each terminal A short-circuit or disconnection determining means for determining whether a distribution line is short-circuited or disconnected by comparing each phase current of the distribution line and the line-to-line voltage between the predetermined two phases included in the data received from the station with a reference value, respectively; 1. A fault section detection system for a power distribution line, comprising short circuit/disconnection section determining means for determining a short circuit fault section or a disconnection fault section based on the determination result of the short circuit/disconnection determination section. Claim 4: A distribution line fault section detection system for detecting a fault section when a fault occurs in a distribution line, wherein a terminal station is placed in each section of a distribution line divided into multiple sections, and each terminal The station includes a voltage sensor that detects the phase voltage of one predetermined phase of the distribution line, a current sensor that detects the current of each phase of the distribution line, and a zero-sequence current that is calculated based on the current detected by the current sensor. a calculation means for calculating a phase difference between a phase current and a predetermined phase voltage of one phase detected by a voltage sensor; data on the phase difference detected by the calculation means; each phase current of the distribution line; A transmitting means for transmitting data on the phase voltage of each phase is provided, and a master station is further provided for receiving data from the terminal station, and the master station includes a transmitting means for transmitting data on the phase voltage of each phase, and a master station for receiving data from the terminal station. based on the distribution of the phase differences, distinguishing a group of terminal stations having a phase difference of approximately 180°,
Ground fault fault section determination means for determining a section existing between adjacent terminal stations among these differentiated terminal stations as a ground fault fault section of the distribution line; A short-circuit or disconnection determination means determines whether the distribution line is short-circuited or disconnected by comparing each phase current of the distribution line and the phase voltage of the predetermined one phase with a reference value; A system for detecting a faulty section of a power distribution line, comprising: a short-circuit/disconnection section determining means for determining a faulty section or a breakage section.