JP2001016762A - Ground failure point locating device for high-voltage signal distribution line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ground failure point locating device for a high-voltage signal distribution line which can surely locate a grounded point, even for a ground failure which can be restored when the current is cut off or even if the ground failure is temporary. SOLUTION: A device has a transmission side transformer T1, whose center tap T0 is grounded, a measuring unit M which measures the instantaneous values of the respective waveforms of voltages VsR and VsT between transmission ends of respective distribution lines R and T and the ground, a failure current flowing into the center tap Tx0 from a ground point and voltages VrR and VrT between reception ends of the respective distribution lines R and T and the ground, ring buffers 2a and 2b in which the measured instantaneous values of the respective waveforms are recorded as waveform data with synchronized timing and a computer 4, which reads out the wavelength data of the measured values of a difference VsR-VsT between the transmission end to ground voltages, a difference VrR-VrT between the reception end to ground voltages and a failure current ig, when a ground failure occurs and calculates the reactance value and a distance Lf of a distribution line R from a transmission end Rs and a ground failure point P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for locating a ground fault in a high-voltage signal distribution line for determining a distance from a power transmission side to a ground fault when a ground fault occurs in a distribution line of a railway or the like. .

[0002]

2. Description of the Related Art Conventionally, a so-called Murray loop is formed by a distribution line as a ground fault point locating device for a distribution line, and when a locating voltage is applied between the distribution line forming the Murray loop and the ground. There is a fault point locating device that measures the magnitude of current flowing through each line and locates a ground fault point based on the magnitude of the current.

FIG. 4 is a view for explaining a location method using a conventional ground fault location apparatus. In FIG. 4, Pw is an AC power supply, 11 and 12 are distribution lines, and CB _p1 is a distribution line 11,
A circuit breaker R _p1 for cutting off the power supply to the power supply line 12 is connected to each of the wires 11, 1 at the power receiving end to form a Murray loop Lm.
2 is a relay for short-circuiting the circuit, R _p2 is the Murray loop L
m, a relay for applying a ground-to-ground voltage E to the distribution lines 11 and 12, Rg is a ground fault resistance, I _p0 is a total current flowing through the Murray loop Lm, and I _P1 and I _P2 are distribution lines 1 respectively.
This is the standardization current flowing through the reference numerals 1 and 12.

[0004] In the above configuration, when a ground fault occurs, the circuit breaker CB _p1 trips (open state) and the distribution line 1
After energization of the 1,12, by forming a Murray Loop Lm by closing the contacts of the relay R _p1, the relay R _p2 on (closed condition), orientation current I _p1, I _p2 Can flow. At this time, each distribution line 1
1, 12 are impedances per unit length (r + j
x) is determined, the magnitude of the locating currents I _p1 and I _p2 is determined by the total length L of the Murray loop Lm and the ground fault point P
To the distance l.

[0005] Therefore, the locating currents I _P0 , I _P1 , I
By comparing the magnitude of _P2 , the ratio of the distance l to the ground fault point P with respect to the total length L of the distribution lines 11, 12 can be obtained as shown in the following equation (1). 1 / L = 2I _p2 / I _p0 −1 Equation (1)

[0006]

However, in the above-mentioned conventional ground fault point locating device, a Murray loop Lm for applying a locating power source E (which may be AC) for locating the ground fault point P is formed. Therefore, it is necessary to cut off the supply of the AC power supply Pw to the distribution lines 11 and 12 so that both distribution lines 11 and 12 are not pressurized. Then, when no pressure was applied, the ground fault accident sometimes recovered temporarily. That is,
The ground fault did not continue in the transient accident.

For this reason, even if the voltage E for locating is applied, the ground fault will not be reproduced and the current I _P0 for locating the ground fault point P will not flow. Could not be done. In such a case, the distribution lines 11 and 12 are used to investigate the cause of the occurrence of the unstable ground fault.
It is necessary to visually confirm the state of the accident, and a great deal of time and labor is wasted in preventing the recurrence of the accident.

The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a ground fault accident or a transient ground fault that can be restored when power is cut off. Even in this case, it is an object of the present invention to provide a ground fault point locating apparatus for a signal high-voltage distribution line, which can reliably locate a ground fault point when a ground fault accident occurs.

[0009]

In order to achieve the above object, a ground fault point locating apparatus for a signal high voltage distribution line according to the present invention is provided for locating a ground fault point when a ground fault occurs in a distribution line. A transmission-side transformer that grounds the intermediate tap, a ground-to-ground voltage at the transmitting end of each distribution line, a fault current flowing from the ground point to the intermediate point, and a ground-to-ground voltage at the receiving end of each distribution line. The difference between the voltage to ground at the transmitting end of each distribution line, the difference between the voltage to ground at each distribution line at the receiving end, and the fault An arithmetic unit that calculates the impedance of the distribution line from the transmitting end to the ground fault using the measured value of the current and calculates the distance from the transmitting end to the ground fault based on the magnitude of the impedance. Having It is characterized.

Therefore, according to the present invention, when a ground fault occurs, the fault current flowing in the distribution line is measured. Therefore, even if the ground fault is restored when the transmission to the distribution line is interrupted, the fault point is detected. Can be determined.
In other words, even if the ground fault accident is such that it is restored when the power supply is cut off, or if it is a temporary ground fault accident, the ground fault point can be reliably located when the ground fault accident occurs. Recurrence can be prevented promptly.

[0011] A device for locating a ground fault point when a ground fault occurs in a distribution line, comprising: a transmission-side transformer for grounding an intermediate tap; a voltage to ground at a transmission end of each distribution line; The measurement unit that measures the instantaneous value of each waveform of the fault current flowing into the intermediate point from the terminal and the voltage to ground at the receiving end of each distribution line, and the waveform instantaneous value of each measured waveform is synchronized as waveform data. The temporary storage unit that records the difference between the voltage to ground at the transmitting end of each distribution line caused by the flow of fault current when a ground fault occurs, the difference between the voltage to ground of each distribution line at the receiving end, and the fault current The magnitude of the reactance of the distribution line from the transmitting end to the ground fault point is determined by reading the waveform data of the measured value from the temporary storage unit and analyzing the measured data, and the magnitude of the reactance is determined based on the magnitude of the reactance. If there is an arithmetic unit that calculates the distance from the end to the ground fault point, even if the ground fault accident is such that it can be restored when power is cut off, or if it is a transient ground fault, A ground fault point can be reliably located when a fault occurs, preventing a recurrence of an accident quickly, and a ground fault point that is hardly affected by unspecified factors such as the magnitude of the ground fault resistance. Can be determined.

The measuring section on the power transmission end and the measuring section on the power receiving end of the distribution line each have a standard time collection device, and record the waveform data using time information obtained from the standard time collection device. When synchronizing the timing, it is possible to extremely easily synchronize with high precision between the measurement units grounded at points distant from each other. That is,
The reactance can be obtained more accurately, and the localization accuracy of the fault point can be improved accordingly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a method of locating a signal high-voltage distribution line using a ground fault fault locating apparatus according to the present invention, wherein R and T are, for example, distribution lines serving as power sources for railway traffic signals. And one end is a power transmission end Rs, Ts, and the other end is a power reception end Rr, Tr. In FIG. 1, for simplicity of explanation, one end side is always fixedly described as the transmitting end Rs, Ts. However, in the actual distribution lines R, T, one end side is a receiving end and other ends as necessary. It is switched to inverted power distribution where the end side is the power transmission end.

Pw is an AC power supply provided at a railway substation
And the isolation transformer T₁Before (Transmission side transformer)
Power is supplied to the transmission ends Rs, Ts of the distribution lines R, T.
Note that this transformer T₁Has an intermediate tap T₀Provided
This intermediate tap T ₀Is the ground resistance R_ngThrough
Grounded. Z₁~ Z_ThreeIs determined by the distribution lines R and T
Is the impedance that occurs_T1, Z_T2Is the distribution line
This is a load such as a traffic light provided between R and T. V_sR,
V_STIs the voltage between ground at the transmitting ends Rs and Ts, V _rR, V
_rTIndicates the voltage between the power receiving terminals Rr and Tr with respect to the ground.
You.

Assume that a ground fault has occurred at a point P on the distribution line R side (hereinafter referred to as a ground fault point P). Then, for example, the by ground fault energized with ground state via the resistor Rg, the fault current ig flows to ground from the power distribution line R, and flows into the intermediate tap T ₀ through the ground resistor R _ng. Further, a fault current ig flows from the transmission end Rs of the distribution line R to the ground fault point P.

At this time, the difference between the ground-to-ground voltages V _sR and V _rR between the transmitting end Rs and the receiving end Rr on the transmission line R side is expressed by the following equation (2).
It becomes as shown in. V _sR −V _rR = Z ₁ (i ₁ + ig + i ₂ ) + Z ₂ (ig + i ₂ ) + Z ₃ × i ₂ Equation (2)

Further, a power transmitting end Ts and a power receiving end T
The difference between the earth-to-ground voltages V _sT and V _rT of r is given by the following equation (3), assuming that the impedance of the transmission line T is the same as that of the transmission line R.
Can be represented as shown in FIG. V _sT −V _rT = Z ₁ (i ₁ + i ₂ ) + Z ₂ (i ₂ ) + Z ₃ × i ₂ Equation (3)

Here, the following equation (4) can be obtained by subtracting the equation (3) from the above equation (2), and by rearranging this, the relation of the equation (5) can be obtained. it can. (V _sR −V _sT ) − (V _rR −V _rT ) = ig (Z ₁ + Z ₂ ) Equation (4) Z ₁ + Z ₂ = ((V _sR −V _sT ) − (V _rR −V _rT )) / Ig Expression (5)

That is, the sum of the impedance of the transmission line R from the transmission end Rs to the ground fault point P (Z ₁ + Z ₂ )
_Are the magnitudes of the loads Z _T1 and Z _T2 connected between the transmission lines R and T, the magnitudes of the currents i ₁ and i ₂ flowing through them, the ground fault resistance R
g can be obtained regardless of the magnitude of the neutral point resistance Rng. The transmission ends Rs, T of the respective distribution lines R, T caused by the flow of the fault current ig at the time of occurrence of the ground fault.
s, the difference between the voltages V _sR and V _{sT to} the ground,
The impedance Z of the distribution line R from the transmitting end Rs to the ground fault point P using the difference between the voltages _VrR and _VrT of the respective distribution lines R and T at the point r and the measured value of the fault current ig.
₁ + Z ₂ can be obtained.

Next, when the distribution line R has a magnitude of an impedance z per unit length (for example, it can be expressed by z = r + jx, and is hereinafter referred to as a unit impedance), a ground fault from the transmission end Rs. The magnitude of the impedance of the distribution line R to the fault point P is a value obtained by multiplying the magnitude of the unit impedance z by the distance Lf to the ground fault point P. That is, the relationship shown in Expression (6) is established, and after obtaining the magnitude of the impedance Z ₁ + Z ₂ , the obtained value is divided by the magnitude of the unit impedance z to obtain a value from the power transmitting end Rs to the ground fault point P. Distance Lf
Can be requested. Z ₁ + Z ₂ = Lf × (r + jx) Equation (6)

In the above equation (6), by paying attention to the magnitude of the reactance x which is a complex component of the impedance Z ₁ + Z ₂ , z, the magnitude of the reactance x is calculated as shown in the following equation (7). Thus, the distance Lf can be obtained. _{jx × Lf = ((V sR} -V sT) - (V rR -V rT)) / ig × sin θ ... (7) however, theta fault current ig and the voltage _{(V sR -V sT) - (} V _rR
−V _rT ).

In the following description, an example of locating the ground fault point P using the magnitude of the reactance x in order to perform locating more concisely and accurately is disclosed. The orientation is not limited to the orientation using the reactance x which is a complex component of the impedance (r + jx).

In any case, according to the present invention, the fault current i
g, the fault current ig and the voltages V _sR , V _sT , V _rR , V _rT of the _respective parts at this time are measured.
The ground fault point P can be located. That is, a relay R _P1 forming a Murray loop Lm for locating a distribution line, a relay R _P2 for supplying a separate locating power, a power source E for locating, etc. It is not necessary to provide a simple device, and the configuration of the ground fault fault locating device can be simplified. Further, maintenance and inspection of the ground fault fault locating device can be simplified. In addition, even if the ground fault is transient and has a degree of recovering immediately, the ground fault point P causing the fault can be located when the first fault current ig flows. .

FIG. 2 is a diagram showing an example of a ground fault point locating apparatus 1 for a signal high voltage distribution line for locating a ground fault point P using the above-described principle. In FIG. 2, members denoted by the same reference numerals as those in FIG. 1 are the same or corresponding members, and thus detailed description thereof will be omitted.

In FIG. 2, the transmission end R of the distribution lines R and T
s, the Ts side, respectively, are provided with a breaker CB _1, the receiving end Rr, the Tr side is provided with a circuit breaker CB _2. And usually breaker CB ₁ is in the ON state (closed), the circuit breaker CB ₂ are disconnected (open), stereotactic distribution that is transmitting from the left side to the right side is performed. Further, when the ground fault occurs, by breaker CB ₁ in the procedure described below is trip (open state), after the circuit breaker CB ₂ is turned on (closed condition), the transmission from the right side to the left side Inversion distribution is performed.

_{T R} and t _T are current probes for measuring currents i _R and i _T flowing through distribution lines R and T, respectively.
A _m These current probes t _R, ammeter connected to t _T, R ₁ is a ground fault protection relay connected in series with the ammeter A _m. Here, the current probes t _R and t _T
Are connected so as to cancel each other at the connection point C when the currents i _R and i _T flowing in the distribution lines R and T are the same (that is, when no failure occurs). When a difference occurs between the currents i _R and i _T ,
Current proportional to the current (i.e. fault current ig) of the difference flows to the ammeter A _m and ground fault protection relay R _1.

Accordingly, the ground fault resistance R
If a ground fault due to g occurs, the fault current i
g is the ammeter A_mAnd ground fault protection relay R₁Detected by
it can. Ground fault protection relay R₁Detects fault current ig
And the circuit breaker CB, respectively. ₁, CB_TwoTrip
As a result, the fault current ig does not flow for a long time.
To do.

T _sR and T _sT are transformers for lowering the voltages V _sR and V _sT of the respective distribution lines R and T at the transmitting ends Rs and Ts to a measurable voltage, _respectively , and M _sR and M _sT are transformers T _sR , T _sT, and the voltage V to ground of each distribution line R, T
_{A voltmeter} for measuring _sR and V _sT , R _2s is the transformer T _sR ,
This is an undervoltage relay that monitors the line voltage of the distribution lines R and T via _TsT .

The same applies to the power receiving ends Rr and Tr.
And the ground voltage V of each distribution line R, T _rR, V_rTCan be measured
Transformer T that reduces voltage_rR, T_rT, This transformer
T_rR, T_rTOf each distribution line R, T via_rR,
V_rTVoltmeter M for measuring_rR, M_rT, Between distribution lines R and T
Undervoltage relay R for monitoring voltage_2rhave.

M indicates a measuring section, and the measuring section M
Is the current probe t_R, T_T, Ammeter A_m,Tiger
Once T_sR, T_sT, T_rR, T_rT, Voltmeter M_sR, M_sT,
M_rR, M _rTAnd so on. That is, the measuring unit M
From the distribution lines R and T at the transmission ends Rs and Ts
Voltage V_sR, V_sT, From the ground point to the intermediate point T₀Because it flows into
Fault current ig, and at the receiving end Rr, Tr of each distribution line
Voltage to ground V_rR, V_rTThe instantaneous value of
Can be measured.

Reference numerals 2 and 3 denote main body units provided at both ends of the distribution lines R and T, respectively, having analog input ports 2a and 3a and digital input ports 2d and 3d, respectively. Each of the orientation unit main bodies 2 and 3 has a standard time collection device G as a part of the measurement unit M, and time information (time information pulse T) obtained from the standard time collection device G is obtained.
Using g), the recording timing of each waveform data input from the analog input ports 2a and 3a is synchronized.

In the _locator main body 2 on the transmitting end side, the above-mentioned instantaneous values of the voltages V _sR and V _sT and the instantaneous value of the fault current ig at the transmitting ends Rs and Ts are input to the analog input port 2a as waveform data. , Digital input port 2d
The ground fault protection relay R ₁ on the power transmission side, the undervoltage relay R _2s , the time information pulse Tg from the standard time collection device G,
And inputs the operation status of the circuit breaker CB _1.

On the other hand, in the locator body 3 on the power receiving end side,
The analog input port 3a is connected to the power receiving terminals Rr and Tr.
Voltage to ground V_rR, V_rT, And the instantaneous value of the fault current ig
Is input as the waveform data, and is input to the digital input port 3d.
Is the ground fault protection relay R on the receiving side ₁, Undervoltage relay R_2r,
And circuit breaker CB_TwoEnter the operation status of.

The orientation units 2 and 3 have ring buffers 2b and 3b as temporary storage units, respectively.
For example, it is recorded together with the time information received from the standard time collection device G. The ring buffers 2b and 3b are capable of storing, for example, respective waveform data for about 10 seconds, and continuously overwrite and store these for about every 10 seconds. further,
The orientation unit main bodies 2 and 3 have communication units 2c and 3c, and communicate with the arithmetic unit 4 such as a computer through the communication units 2c and 3c to convert each waveform data measured. Can be sent to

The arithmetic unit 4 has a communication unit 4a for making it possible to communicate with each of the orientation units 2 and 3 through a communication line such as a telephone line, for example, and each measurement value written in the ring buffers 2b and 3b. By collecting measurement value data representing the instantaneous values of V _sR , V _sT , V _rR , V _rT , and ig and analyzing the data, the ground fault point P can be located.

FIG. 3 is a diagram for explaining the operation of each unit when a ground fault occurs using the ground fault point locating apparatus 1 for a signal high-voltage distribution line having the above configuration. Hereinafter, the operation of the ground fault fault locating apparatus 1 of the signal high-voltage distribution line according to the present invention will be described with reference to FIGS.

That is, when a ground fault occurs at time t ₀ , a fault current ig flows through the transformer T ₁ on the transmission end side, and a change occurs in the ground-to-ground voltage V _sR of the distribution lines R and T. The fault current ig detects the ground fault protection relay R ₁ is operated, when to trip the circuit breaker CB ₁ simultaneously,
The locator start signal Ss is generated in the locator body 2 according to the condition that the circuit breaker CB ₁ is in the ON state and the ground fault protection relay R ₁ is operated. At the same time it records the time of the operation time of the ground fault protection relay R _1.

The instantaneous values of the measured values V _sR , V _sT , and ig for a total of 10 seconds, for example, 0.5 seconds before and 9.5 seconds after the time t _{1 at which the locator} start signal Ss is _input , are shown. The measurement value data is stored together with the time data from the ring buffer 2b, and this is used as the measurement value storage data. Then, and lack breaker CB ₁ at time t ₂ is tripped distribution lines R, because the potential difference is eliminated between the T voltage relay R _2S
Works. Note that in the power transmission end side, this so ignores the operation of the undervoltage relay R _2S from the operation of the ground fault protection relay R ₁ which precedes example 10 seconds, to operate in accordance with the operation of the undervoltage relay R _2S There is no.

On the other hand, at the time point t ₂ , the circuit breaker CB ₁
Trips, there is no potential difference between the distribution lines R and T on the receiving end side, so the undervoltage relay R on the receiving end side
_2R operates detects this, breaker CB ₂ by undervoltage relay R _2R at time t ₃ is turned. At this time, a locator start signal Sr is generated in the locator body 3 on the power receiving end side. Then, the locator activation signal Sr
Saved from the ring buffer 3b is entered time point t _3, for example, from front to 4 seconds, after 6 seconds of a total of 10 seconds of measurement V _rR, V _rT, together with the time data measurements data representing the instantaneous value of ig, which Is stored data of measured values.

Next, when the circuit breaker CB ₂ is turned on at the time point t ₄ , power is supplied from the power receiving end side to the power transmission end side, and inverted power distribution is performed. In the description of the specification of the present application, the left side (usually) is referred to as the power transmission end side and the right side is referred to as the power reception end side even when inverted power distribution is performed in order to unify the expressions. It goes without saying that in the state of power distribution, the location processing may be performed by switching between the power transmission end side and the power reception end side.

When the ground fault continues at time t ₄ when the circuit breaker CB ₂ is turned on and the fault current ig flows,
Ground fault protection relay R ₁ in the receiving end to trip the circuit breaker CB ₂ detects the fault current ig at time t _5. In this way, the distribution line R, T becomes open state at time t _6, to prevent the fault current ig continues to flow. Also, orientation body 3 records the operation time of the ground fault protection relay R _1.

On the other hand, the locator main body 2 calls the arithmetic unit 4 and, based on the stored data, the ground fault protection relay R on the power transmission side.
The measured value V _{sR for} three cycles including the operation time marker of ₁ ,
The measured value data representing the instantaneous value of V _sT , ig is transmitted to the arithmetic unit 4. Next, the waveform data representing the instantaneous values of the measured values V _rR and V _rT for three cycles corresponding to this is transferred to the arithmetic unit 4 from the data stored in the orientation unit main body 3. In addition,
The connection between the orientation units 2 and 3 and the arithmetic unit 4 may be performed using a general telephone line or a dedicated line including wireless.

By doing so, the synchronized ties are
Measured value V_sR, V_sT, Ig, V_rR, V_rT
Can be obtained. The arithmetic unit 4 performs these measurements
Value V _sR, V_sT, V_rR, V_rT, Ig are analyzed. analysis method
As an example, each of the measured values V_sR, V_sT, V_rR,
V_rT, Ig are subjected to Fourier expansion to obtain harmonic components
Can be removed. In addition, the calculation of the above equation (7)
Is performed, the distance from the transmitting end Rs to the ground fault point P is
Finding the size of the reactance of the distribution line R
And the magnitude of this reactance is
By dividing by reactance x, from the transmitting end Rs
The distance Lf to the ground fault point P can be located.

The orientation calculation by the arithmetic unit 4 uses the waveform data V _sR , V _sT , V _rR , V _rT , and ig for three cycles from time t _{0 to} t _2. Since the distance Lf to the ground fault point P is determined by using the first fault current ig at the time when the fault occurs, if a ground fault occurs, even if the ground fault is switched to the reverse power distribution, the fault is detected. Even after recovery, the ground fault point P can be located.

However, the present invention is not limited to this. For example, at time t ₄ after inversion power distribution,
Each measured value V _sR , V _sT , V _rR , V _rT , ig during t ₆ (the fault current ig in this case is a current flowing into the intermediate tap T ₀ of the transformer T ₂ on the receiving end side, and the distance Lf obtained is Is the distance measured from the power receiving end side). Furthermore, the ground fault point P measured in the state of
And the ground fault point P measured in the state of inverted power distribution
The more reliable ground fault P
May be performed.

In the above example, the measured values V _sR , V _sT ,
In order to measure the waveform data of _VrR , _VrT , and ig at the synchronized timing, the time information pulse Tg of the standard time collection device G is used, so that the locator bodies 2, 3 arranged at distant points can be used. For example, synchronization can be achieved with an error of several μs or less. G for standard time collection device G
It can be implemented using a PS receiver or the like.

It is also possible to receive a standard time signal of a long wave JJY (a long wave standard radio wave transmitted from June 1999) and use it as a synchronization signal. In addition, for example, an extremely accurate clock such as an atomic clock may be incorporated in each of the two target body 2 and 3. It is also possible to connect a communication line for synchronization and use the communication line for synchronization, or to synchronize by superimposing a frequency-modulated synchronization signal on the distribution lines R and T.

In the above example, the size of the ring buffers 2b and 3b as the temporary storage unit is set to about 10 seconds as an example, but the present invention does not limit the size of the ring buffers 2b and 3b. Similarly, the measured values V _sR for 10 seconds as an example from the ring buffers 2b and 3b,
The instantaneous values of V _sT , V _rR , V _rT , and ig are stored.
It discloses an example in which the orientation calculation using the waveform data of the cycle, are not intended to limit the time t ₁ to be its length and a reference to the embodiments described above. For the time being back 2b,
The larger the size of 3b, the better the length of the waveform data to be stored and orientated.

[0049] Further, the ring buffer 2b, as a measure data to be stored in 3b, each distribution line R, the difference V _sR -V _sT of ground voltage T, then after calculating V _rR -V _rT, stores the difference May be. In this case, the ring buffer 2
The number of data stored in b and 3b can be reduced, and the measured value data for a longer time can be stored with the same capacity.

In addition, in the above example, of the distribution lines R and T,
Although an example in which a ground fault has occurred in the distribution line R is considered, it is needless to say that the ground fault point P can be located in the same procedure when a ground fault occurs in the distribution line T. In this case, it can be determined that a fault has occurred when the voltage is greatly reduced due to a ground fault.

In the above example, the distribution lines R and T are always 2
Although the case of a main line is disclosed, the present invention does not limit the number of distribution lines to two lines. In other words, it is possible to locate the ground fault point P in the same manner even with three lines.

[0052]

As described above, according to the present invention, when a ground fault occurs, the fault current flowing in the distribution line is measured, so that the ground fault is restored even when the power transmission to the distribution line is cut off. Even if it is a temporary ground fault accident, the fault point can be located. That is, when a ground fault occurs, the ground fault point can be reliably located, and recurrence of the fault can be quickly prevented. The measuring unit on the transmitting end and the measuring unit on the receiving end of the distribution line each have a standard time collection device, and use the time information obtained from the standard time collection device to synchronize the recording timing of the waveform data. In this case, highly accurate synchronization can be achieved very easily between the measurement units grounded at points distant from each other. That is, the localization accuracy of the fault point can be increased accordingly.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for locating a high-voltage signal distribution line using a ground fault fault locating apparatus according to the present invention.

FIG. 2 is a diagram showing an example of a ground fault fault locating apparatus for a signal high-voltage distribution line according to the present invention.

FIG. 3 is a diagram for explaining an operation of the ground fault fault locating device for the signal high-voltage distribution line.

FIG. 4 is a diagram illustrating a location method using a conventional ground fault fault location device.

[Explanation of symbols]

1 ... ground fault fault locating device for signal high voltage distribution line, 2b, 3
b: temporary storage unit, 4: operation unit, G: standard time collection device,
ig: fault current, M: measuring section, R, T: distribution line, T ₀ ...
Intermediate tap, T ₁ ... Transmission side transformer, Tg ... Time information, R
s ... the sending end, Rr ... receiving _{end, V sR, V sT, V} rR, V rT ...
Voltage to ground.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor ▲ Takao Hashio 4-4-1-10 Segawa, Minoh-shi, Osaka Inside Tsuda Denki Keiki Co., Ltd. (72) Tetsuzo Kitagawa 4-4-2 Segawa, Minoh-shi, Osaka No. 10 Tsuda Denki Keiki Co., Ltd. F term (reference) 2G033 AA04 AB01 AC02 AD11 AG12 5G058 EE01 EF03 EF04 EG15 EH02 EH03

Claims (3)

[Claims] An apparatus for locating a ground fault point when a ground fault occurs in a distribution line, comprising: a transmission-side transformer for grounding an intermediate tap; and a voltage to ground at a transmission end of each distribution line.
A measuring unit that measures the fault current flowing from the ground point to the intermediate point and the voltage to ground at the receiving end of each distribution line, and the transmission end of each distribution line caused by the fault current flowing when a ground fault occurs The difference between the voltage to ground at, the difference between the voltage to ground of each distribution line at the receiving end, and the magnitude of the impedance of the distribution line from the transmitting end to the ground fault using the measured value of the fault current, A calculating unit for calculating a distance from the power transmitting end to the ground fault point based on the magnitude of the impedance, and a ground fault point locating device for the signal high-voltage distribution line. 2. An apparatus for locating a ground fault point when a ground fault occurs in a distribution line, comprising: a transmission-side transformer for grounding an intermediate tap; and a ground-to-ground voltage at a transmission end of each distribution line.
A measuring unit that measures the instantaneous value of each waveform of the fault current flowing from the ground point to the intermediate point, and the voltage to ground at the receiving end of each distribution line, and the waveform at the timing that synchronizes the instantaneous value of each measured waveform A temporary storage unit that records data, a difference in ground-to-ground voltage at the transmitting end of each distribution line caused by a fault current flowing when a ground fault occurs, a difference in ground-to-ground voltage of each distribution line at the receiving end, and a fault By reading and analyzing the waveform data of the measured current value from the temporary storage unit, the magnitude of the reactance of the distribution line from the transmitting end to the ground fault point is obtained, and the magnitude of the reactance is used to determine the magnitude of the reactance from the transmitting end to the ground. And a calculation unit for calculating a distance to a ground fault point. 3. The measuring section on the transmitting end and the measuring section on the receiving end of the distribution line each have a standard time collection device, and the waveform data is obtained by using time information obtained from the standard time collection device. 3. The apparatus for locating a ground fault in a signal high-voltage distribution line according to claim 2, wherein the recording timing is synchronized.