JPH068833B2 - Fault current detection display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a fault current detection display device for displaying a short-circuit / ground-fault when a short-circuit or ground-fault occurs in a distribution line. Is.

(Prior Art) Conventionally, when a ground fault occurs in a distribution line, firstly, a substation breaker is opened and then a substation is opened from the viewpoint of early detection of an accident section, separation of a failure section and early transmission of a sound section. The circuit breaker is reclosed, and the sub-switches on the power supply side are sequentially turned on to re-transmit power to a healthy section, and the substation circuit breaker is shut off again when a ground fault section is reached.

Then, when the circuit breaker of the substation is closed again, the section switching circuit that divides the ground fault section is locked in an open state, only the ground fault section is separated, and power is retransmitted only in the sound section. , Searching for a ground fault section. Then, when a ground fault fault section can be searched for, the ground fault point is detected by repeatedly performing the insulation resistance measurement of the related distribution equipment provided on each utility pole in the fault section.

(Problems to be Solved by the Invention) As described above, in the related art, after the ground fault section is known, the related distribution equipment arranged on the utility pole or the like existing in the ground fault section is sequentially insulated for each utility pole. There was a work problem that it took a lot of time because the measurement was done,
It took time to detect the ground fault.

(Means for Solving Problems) An object of the present invention is to solve the above problems and to provide a fault current detection display device having excellent insulation performance as compared with a conventional ground fault display device.

That is, the fault current detection display device of the present invention suspends and supports a detector for each phase on the distribution line of each phase, and utilizes the change of the magnetic field generated in the distribution line of the corresponding phase for the detector of each phase. To detect the phase current flowing in the distribution line, and to detect the voltage of the distribution line by using the optical fiber current sensor that outputs an optical signal based on the change in the magnetic field and the change in the electric field that occurs in the distribution line of the corresponding phase. , An optical fiber voltage sensor that outputs an optical signal based on the change in the electric field, and a detector provided in an intermediate phase of the distribution line further includes an optical signal output from the optical fiber current sensor of each phase. A first photoelectric conversion means for converting to an electric signal, a second photoelectric conversion means for converting an optical signal output from the optical fiber voltage sensor of each phase into an electric signal, and from the first photoelectric conversion means Based on the signal, the phase current A short circuit detecting means for detecting a short circuit when the bell is present, and a zero phase current determining means for detecting a zero phase current based on a signal from the first photoelectric conversion means of each phase and performing a phase determination of the zero phase current. , A zero-phase voltage discriminating means for detecting a zero-phase voltage based on a signal from the second photoelectric conversion means of each phase and discriminating the phase of the zero-phase voltage, and a phase discrimination result of the zero-phase current discriminating means and zero. Based on the phase discrimination result of the phase voltage discrimination means and the discrimination result of both, the phase judgment means that outputs the judgment signal of either one of the ground fault point from the power supply side to the load side, and the no-voltage state of the distribution line. No-voltage detection means for detecting, short-circuit detection of the short-circuit detection means, short-circuit display output means for outputting a short-circuit display signal based on the detection of no voltage of the no-voltage detection means, the determination of the phase determination means, no Directionality based on the detection of no voltage by the voltage detection means In response to the display signal from the ground fault directional display output means, the short-circuit indicator that displays a short circuit in response to the display signal from the short-circuit display output means, and the display signal from the ground fault directional display output means. The gist of the present invention is to provide a ground fault direction indicator that displays a directional ground fault.

(Operation) With the above configuration, when a ground fault occurs, the optical fiber current sensor of each phase detects a fault current flowing in the distribution line based on the change in the magnetic field of the distribution line, and outputs an optical signal based on the change in the magnetic field. . Then, the first photoelectric conversion means converts the optical signal from the optical fiber current sensor into an electric signal. The zero-phase current discrimination means detects the zero-phase current based on the signal from the first photoelectric conversion means of each phase and discriminates the phase of the zero-phase current.

The optical fiber voltage sensor detects the voltage of the distribution line by utilizing the change in the electric field generated from the distribution line, and outputs an optical signal based on the change in the electric field. Then, the second photoelectric conversion means converts the optical signal output from the optical fiber voltage sensor into an electric signal.

The zero-phase voltage determination means detects the zero-phase voltage based on the signal from the first photoelectric conversion means of each phase and determines the phase of the zero-phase voltage. The phase discriminating means discriminates whether the ground fault point is the power source side or the load side based on the discriminating result of both the phase discriminating result of the zero phase current discriminating means and the phase discriminating result of the zero phase voltage discriminating means. Is output.

Then, when the circuit breaker in the substation trips due to the fault current, the no-voltage detecting means detects the no-voltage state of the distribution line. The ground fault directional display output means outputs a directional display signal based on the determination of the phase determination means and the non-voltage detection of the no-voltage detection means, and the ground fault directional indicator responds to the display signal. A directional ground fault is displayed.

Further, when a short-circuit accident occurs, the optical fiber current sensor of each phase operates based on the change in the magnetic field of the distribution line as in the case of the ground fault, and the short-circuit detection means is the first photoelectric conversion means. A short circuit is detected when the phase current is at the short circuit current value level based on the signal of.

Then, when the circuit breaker in the substation trips due to the fault current, the no-voltage detecting means detects the no-voltage state of the distribution line. The short-circuit display output means outputs a short-circuit display signal based on the short-circuit detection by the short-circuit detection means and the non-voltage detection by the no-voltage detection means. The short circuit indicator displays a short circuit in response to a display signal from the short circuit display output means.

(Embodiment) An embodiment embodying the present invention will be described below with reference to FIGS.

First, third, and second detectors A, C, and B are attached to the distribution line L in order from one side, and the first detector A, the second detector B, and the third detector are attached. The fault current detection display device 1 is configured from the device C.

Since the first and second detectors A and B have the same configuration, the first detector A will be described. The first detector A is roughly divided into a detection unit α, a transmission unit 26, and a power supply unit 32. Has been done.

The detection unit α will be described.

The optical fiber current sensor 2 (hereinafter referred to as a current sensor) is placed on the upper part of the case of the detector A and arranged so as to be close to the distribution line L. This current sensor 2 has a magneto-optical effect (in particular, a Faraday effect; when linearly polarized light is passed along the direction of a magnetic field, its plane of polarization rotates), a polarizer 4 is arranged at one end side of a Faraday element 3. An analyzer 5 inclined by π / 4 with respect to the polarizer 4 is arranged on the other end side. The Faraday element 3 has a large Verdet constant, for example, bismuth silicon oxide (Bi12SiO2).
0), rare earth iron garnet (Y 3 Fe 5 O 12) and the like are used.

One end of an optical fiber 6 that transmits incident light is arranged relative to the polarizer 4. A light emitting element 9 composed of an emitting diode is connected to the other end of the optical fiber 6 of the current sensor 2. A first light emitting element driving circuit 10 is connected to the light emitting element 9, and the first light emitting element driving circuit 10 constantly drives a certain amount of random polarized light (see FIG. 8A) to emit light. ing.

Therefore, the current sensor 2 converts the randomly polarized light, which the polarizer 4 has entered through the optical fiber 6, into linearly polarized light (see FIG. 8 (b)), and the Faraday element 3 is arranged along the direction of the magnetic field. When the linearly polarized light passes, the plane of polarization of the linearly polarized light is rotated by the rotation angle φ (see FIG. 8 (c)) in proportion to the change in the magnetic field. Further, the analyzer 4 converts the emitted light having the rotation angle φ inclined by the Faraday element 3 into a light amount change component P1 and a light amount change component P2.

Also, one ends of optical fibers 7 and 8 are arranged relative to the analyzer 5, respectively. The other ends of the optical fibers 7 and 8 are connected to current sensor light-receiving elements 11 and 12 as the same photoelectric conversion means, which are photodiodes. The current sensor light receiving elements 11 and 12 convert the light amounts of the x-axis direction component P1 and the y-axis direction component P2 incident from the optical fibers 7 and 8 into an electric signal, and the electric signal is sent to a current value signal processing circuit 13. It is designed to output.

The current value signal processing circuit 13 is configured to combine both input electric signals to calculate the rotation angle φ and further to calculate a current value proportional to the magnetic field H. Then, the current value signal processing circuit 13 outputs the current value signal Sj corresponding to the obtained current value.
1 is output to the transmission circuit 26 described later.

Similar to the current sensor 2, an optical fiber voltage sensor 14 (hereinafter referred to as a voltage sensor) is provided near the distribution line L with respect to the detector 1. The voltage sensor 14 is provided on one end side of a Pockels element 15 having an electro-optical effect (particularly the Pockels effect; the property that the refractive index for a light wave having an electric field in the x and y directions changes in proportion to the applied voltage). Is a polarizer 17 through a λ / 4 plate (λ; wavelength) 16
And the analyzer 18 is arranged on the other end side.

The Pockels element 15 is, for example, bismuth silicon oxide (Bi12SiO20) or magnetic garnet (B
i 2 Ge 3 O 12) and the like are used.

One end of an optical fiber 19 that transmits incident light is arranged relative to the polarizer 17. A light emitting element 20 including a light emitting diode is connected to the other end of the optical fiber 19. The light emitting element 20 includes the first light emitting element drive circuit 1
0 is connected, and the first light emitting element drive circuit 10 constantly drives a predetermined amount of random polarized light (see FIG. 8A) to emit light.

Therefore, the voltage sensor 14 converts the random polarized light, which the polarizer 17 has entered through the optical fiber 20, into linearly polarized light, and the λ / 4 number 16 is 90 degrees with respect to the linearly polarized light having electric fields in the x and y directions. The optical phase difference of
(D) Refer to the figure). Furthermore, Pockels element 1
5 is the electro-optic effect (x, proportional to the applied voltage,
Due to the property that the refractive index for a light wave having an electric field in the y direction changes, the circularly polarized light that has entered is made elliptically polarized (see FIG. 8 (e)). The analyzer 18 converts the elliptically polarized light output from the Pockels element 15 into x-axis direction components Q1 and y.
Convert to the axial component Q2.

Further, one ends of the optical fibers 21 and 22 are respectively arranged relative to the analyzer 18, and the other ends of the optical fibers 21 and 22 are the light receiving element 23 for the voltage sensor as the second photoelectric conversion means composed of a photodiode. 24 is connected. The light receiving elements 23 and 24 for the same voltage sensor are the optical fiber 2
The amounts of light of the x-axis direction component Q1 and the y-axis direction component Q2 incident from 1 and 22 are converted into an electric signal, and the electric signal is output to the voltage signal processing circuit 25.

The voltage value signal processing circuit 25 synthesizes both input electric signals to calculate an electric field E, and further calculates a voltage value flowing through the distribution line L based on the electric field E. Then, the voltage value signal processing circuit 25 outputs the current value signal Sv1 corresponding to the obtained voltage value to the transmission circuit 26 described later.

The current sensor 2, voltage sensor 14, first light emitting element drive circuit 10, current value signal processing circuit 13, voltage value signal processing circuit 25, light emitting elements 9 and 20, current sensor light receiving element 1
1, 12, the voltage sensor light-receiving elements 23, 24, and the like form a detection unit α.

The transmission circuit 26 serving as a transmission unit includes a second light emitting element driving circuit 27 and a pair of light emitting elements for current value signals, which are connected to the second light emitting element driving circuit 27 and include a light emitting diode that emits visible light or infrared light. 28 and a voltage value signal light emitting element 29. Each of the light emitting elements 28, 29 is disposed on the side of the case of the first detector A so as to correspond to the light receiving elements 33, 35 for the current value signal and the voltage value of the third detector C described later. (See FIG. 1). And
The second light-emitting element drive circuit 27 uses the current value signals Sj1,
And the light emitting elements 28 and 29 are driven to emit light based on the voltage value signal Sv1.

In FIG. 5, a current transformer CT attached to the distribution line L is provided in the upper part of the case of the first detector A, and a rectifier circuit 30 is connected to the secondary side of the current transformer CT. . A series circuit of a resistor R1, a collector / emitter of a transistor Tr, a resistor R2, and a rechargeable battery 31 is connected between the plus and minus terminals of the rectifier circuit 30. A resistor R3 is connected between the negative terminal of the resistor R1 and the negative terminal of the rectifier circuit 30, and a Zener diode ZD is connected between the base terminal of the transistor Tr and the negative terminal of the rectifier circuit 30.

Rectifier circuit 30, resistor R1, transistor Tr, resistor R2, battery 31, resistor R3, Zener diode Z
A power supply circuit 32 as a power supply unit is configured from D and D. Then, the power supply circuit 32 supplies a drive current to each circuit.

The current value signal light emitting element 28 and the voltage value signal light emitting element 29 of the second detector B output the current value signal Sj2 and the voltage value signal Sv2 similarly to the first detector A.

Next, the third detector C will be described with reference to FIG.

In the third detector C, the same components as those of the first and second detectors A and B are designated by the same reference numerals for convenience of description.

The third current detector C is equipped with a detector α having the same structure as the first and second detectors A and B attached to the other two phases. The current value signal processing 13 and the voltage value signal processing circuit 25 of the third detector C output the current value signal Sj3 and the voltage value signal Sv3.

The current value signal light emitting element 28 and the voltage value signal light emitting element 29 of the first detector A are provided on one side of the case of the third detector C.
The light-receiving element 33 for the current value signal and the light-receiving element 35 for the voltage value signal are respectively exposed and arranged in correspondence with the above. or,
On the other side of the case of the third detector C, a current value signal light emitting element 28 and a voltage value signal light emitting element 29 of the second detector B are provided.
Corresponding to and, the current value signal light receiving element 34 and the voltage value signal light receiving element 36 are respectively exposed and arranged.

The current value signal light receiving elements 33 and 34 and the voltage value signal light receiving elements 35 and 36 are the current value signal light emitting element 28 and the voltage value signal light emitting element of the first detector A and the second detector B, respectively. An optical signal from the element 29 is input (received), and based on the optical signal, converted into current value signals Sj1 and Sj2 and voltage value signals Sv1 and Sv2, respectively, and output.

First and second current level determination circuits 37 and 38 are connected to the current value signal receiving elements 33 and 34, respectively.
A third current level determination circuit 39 is connected to the current value signal processing circuit 13 of the third detector C. Each current level determination circuit 37, 38, 39 is adapted to detect whether or not the current level based on the input current value signals Sj1, Sj2, Sj3 is a predetermined level.

A common short-circuit detection circuit 40 as short-circuit detection means is connected to one output terminal of each current level determination circuit 37, 38, 39, and an amplifier 41 is connected to each of the other output terminals. The output terminals of the amplifiers 41 are connected to each other to form a zero-phase current discriminating circuit 42 as a zero-phase current discriminating means, and the zero-phase current discriminating circuit 42 is connected to a phase discriminating circuit 43 described later. A resistor R4 is connected between the input and output terminals of the amplifier 41.

The short circuit detection circuit 40 is the same as the current level determination circuits 37, 3
When it is detected that 8 and 39 are equal to or higher than a predetermined level, if the level is a short circuit current value level, a short circuit detection signal is output. On the contrary, when the current level determination circuits 37, 38 and 39 determine that the current level is lower than the predetermined level, the signal is amplified by the amplifier 41, and the zero phase current determination circuit 42 outputs the zero phase current based on the signal. The phase signal of the detected zero-phase current is output to the phase determination circuit 43.

An AND circuit as short-circuit display output means is connected to the output terminal of the short-circuit detection circuit 40, and the AND circuit 44 inputs the short-circuit detection signal as a signal corresponding to a logical value 1. A short circuit indicator 45 is connected to the output terminal of the AND circuit 44, and when a non-voltage detection signal corresponding to a logic value 1 and the short circuit detection signal described later are both input, a short circuit display drive current corresponding to a logic value 1 is output. The short-circuit indicator 45 is output for short-circuit display.

The short-circuit indicator 45 is arranged on the lower surface of the third detector C (see FIG. 2).

The voltage signal receiving elements 35 and 36 and the third detector C
The voltage value signal processing circuit 25 of No. 4 has a phase determination circuit 4 as a phase determination unit through a zero phase voltage determination circuit 46 as a zero phase voltage determination unit star-connected through resistors R5 to R7.
Connected to 3.

Therefore, based on the voltage value signals Sv1 and Sv2 for two phases from the voltage value signal light receiving elements 35 and 36 and the voltage value signal Sv3 for one phase from the voltage value signal processing circuit 25 of the third detector C. The zero phase voltage is detected and the phase signal of the zero phase voltage is output to the phase determination circuit 43.

The phase determination circuit 43 compares the phase signal from the zero-phase current determination circuit 42 with the phase signal from the zero-phase voltage determination circuit 46, and based on the phase comparison, the ground fault point is the power source side of the display device. Either the load side or the load side determination signal is output.

That is, when the phase of the zero-phase current is close to 0 to 110 degrees ahead of the phase of the zero-phase voltage, it is determined that the ground fault point is on the load side, and the load-side determination signal is output. When the phase of is shifted by 180 degrees, the ground fault point is determined to be the power source side, and the power source side determination signal is output. A display direction selection circuit 47 as a ground fault directivity output means is connected to the output terminal of the phase determination circuit 43.

A non-voltage detection circuit 48 as a non-voltage detection means is connected to the output side of the zero-phase voltage discrimination circuit 46, and its output terminal is connected to the AND circuit 44 and the display direction selection circuit 47. When the no-voltage detection circuit 48 detects that the output signal from the zero-phase voltage determination circuit 46 is no voltage, it outputs a no-voltage detection signal corresponding to a logical value 1 to the AND circuit 44 and the display direction selection circuit 47. It is supposed to do.

The output direction of the display direction selection circuit 47 is connected to the external direction indicator 49, and the non-voltage detection signal corresponding to the logic value 1 and the determination signal of either the power supply side or the load side are input together. When, the logical value 1 based on the judgment signal
The power supply side direction display drive current or the load side direction display drive current corresponding to is output.

The ground fault direction indicator 49 is arranged on the lower surface of the third detector C (see FIG. 2), and its display section is the power source side display section 49a.
And a load side display section 49b are provided, and when the power supply side determination signal is input to the display direction selection circuit 47, the power supply side display section 49a displays the power supply side direction and the load side display drive current is input. Then, the load side display portion 49b displays the load side direction.

The operation of the fault current detection display device configured as described above will be described.

When a steady load current is flowing through the distribution line L, the power supply circuit 32 of the first, second and third detectors A, B and C provided in each phase is slightly changed from the current transformer CT. Is output, and the transformed current is rectified by the rectifier circuit 30 to charge the battery 31.

Now, when a ground fault occurs in any one-phase distribution line L and a fault current flows in the distribution line L, the current sensors 2 of the detectors A, B, C of the respective phases detect the fault current. That is, the current sensor 2 converts the randomly polarized light that the polarizer 4 has entered through the optical fiber 6 into linearly polarized light, and the Faraday element 3 rotates the polarization plane of the linearly polarized light by a rotation angle φ in proportion to the change in the magnetic field. . Further, the analyzer 4 converts the emitted light having the rotation angle φ inclined by the Faraday element 3 into a light amount change component P1 and a light amount change component P2.

Then, the current sensor light receiving elements 11 and 12 convert the light amounts of the light amount change component P1 and the light amount change component P2 incident from the optical fibers 7 and 8 into an electric signal, and output the electric signal to the current ground signal processing circuit 13. To do. The current value signal processing circuit 13 synthesizes the two inputted electric signals to calculate the rotation angle φ, and further calculates a current value proportional to the magnetic field H. Then, the current value signal processing circuit 13 outputs a current value signal Sj1 (current value signal Sj2 in the second detector B) corresponding to the obtained current value to the second light emitting element drive circuit 27 of the transmission circuit 26. To do.

The second light-emitting element drive circuit 27 uses the current value signals Sj1,
And the light emitting elements 28 and 29 are driven to emit light based on the voltage value signal Sv1. This light receiving element 33 for current value signal
Respectively input (receive) optical signals from the current value signal light emitting elements 28 of the first detector A and the third detector C, and based on the optical signals, the current value signal Sj1 (second detector B
In the above, the current value signal Sj2) is converted and output.

The current level determination circuits 37, 38, 39 respectively detect whether or not the current level based on the input current value signals Sj1, Sj2, Sj3 is a predetermined level,
When the current level determination circuits 37, 38, 39 determine that the current level is below the predetermined level, the signal is amplified by the amplifier 41, and the zero-phase current determination circuit 42 detects the zero-phase current based on the signal, and the zero-phase current is detected. Phase determination circuit 4 for phase signal of phase current
Output to 3.

On the other hand, when the fault current flows through the distribution line L, the voltage sensors 14 of the first, second and third detectors A, B and C detect changes in the electric field.

That is, the voltage sensor 14 of each of the detectors A, B, and C converts the randomly polarized light that the polarizer 17 has entered through the optical fiber 20 into linearly polarized light, and the λ / 4 number 16 is an electric field in the x and y directions. An optical phase difference of 90 ° is given to the same linearly polarized light to convert it into circularly polarized light. Furthermore, the Pockels element 15
Is the electro-optical effect (x, y in proportion to the applied voltage
The incident circularly polarized light is changed to elliptically polarized light due to the property that the refractive index changes with respect to a light wave having an electric field in the direction. And
The analyzer 18 converts the elliptically polarized light output from the Pockels element 15 into an x-axis direction component Q1 and a y-axis direction component Q2.

Further, the voltage sensor light receiving elements 23 and 24 convert the light amounts of the x-axis direction component Q1 and the y-axis direction component Q2 incident through the optical fibers 21 and 22 into an electric signal, and the electric signal is a voltage value signal processing circuit. Output to 25. The voltage value signal processing circuit 25 synthesizes both input electric signals to calculate the electric field E, and further calculates the voltage value of the distribution line L based on the electric field E. Then, the voltage value signal processing circuit 25 transmits the current value signals Sv1 and Sv2 corresponding to the obtained voltage value to the transmission circuit 26.
Output to.

Transmission circuit 2 in the first detector A and the second detector B
The second light emitting element drive circuit 27 of No. 6 has the voltage value signal Sv.
The light emitting element 29 is driven to emit light based on 1, Sv2.

A pair of light receiving elements 3 for voltage value signals in the third detector C
Reference numeral 5 respectively inputs (receives) optical signals from the voltage value signal light emitting elements 29 of the first detector A and the second detector B,
Based on the optical signal, the voltage value signals Sv1 and Sv2 are converted and output.

The zero-phase voltage discriminating circuit 46 includes the voltage value signal light receiving elements 35, 3
The zero-phase voltage is detected based on the two-phase voltage value signals Sv1 and Sv2 from 6 and the one-phase voltage value signal Sv3 from the voltage value signal processing circuit 25 of the third detector C, and the zero phase is detected. The voltage phase signal is output to the phase determination circuit 43.

The phase determination circuit 43 compares the phase signal from the zero-phase current determination circuit 42 with the phase signal from the zero-phase voltage determination circuit 46.

At this time, when the phase of the zero-phase current is close to 0 to 110 degrees ahead of the phase of the zero-phase voltage, it is determined that the value-fault point is on the load side, and the load-side determination signal is output. On the contrary, when the phase of the zero-phase current is shifted by 180 degrees, it is determined that the ground fault point is the power source side, and the power source side determination signal is output to the display direction selection circuit 47.

When the circuit breaker of the substation trips due to a fault current flowing through the distribution line L while the power supply side or load side determination signal is being output to the display direction selection circuit 47, the distribution line L is in a no-voltage state. Therefore, the zero-phase voltage discrimination circuit 46
The output from is no voltage.

Then, the no-voltage detection circuit 48 detects that the output signal from the zero-phase voltage determination circuit 46 has no voltage, and outputs the no-voltage detection signal corresponding to the logical value 1 to the display direction selection circuit 47. As a result, the display direction selection circuit 47 inputs both the non-voltage detection signal corresponding to the logical value 1 and the determination signal on either the power supply side or the load side, and responds to the logical value 1 based on the determination signal. The power supply side direction display drive current or the load side direction display drive current is output.

Then, the ground drive direction indicator 49 displays the power supply side display section 49a or the load side display section 49b by this display drive current. Therefore, on the lower surface of the third detector C, the power source side or load side display portions 49a and 49b of the ground fault direction indicator indicate the direction, so that the spectator visually recognizes the indication and the fault current detection display device 1 Judge whether the ground fault accident point is the power supply side or the load side from the mounting point where is provided.

In addition, a short circuit accident occurs in the distribution line L and a fault current (short circuit current)
When the current flows, the current sensor 2 of each of the detectors A, B, and C operates in the same manner as described above, and each of the current level determination circuits 37, 38, and 39 in the third detector C causes the input current value. It is determined whether the current level based on the signals Sj1, Sj2, Sj3 is a predetermined level.

The short circuit detection circuit 40 is the same as the current level determination circuits 37, 3
When it is determined that any one of 8 and 39 is equal to or higher than the predetermined level, if the level is the short circuit current value level, the short circuit detection signal is output.

Then, the AND circuit 44 inputs the short circuit detection signal as a signal corresponding to the logical value 1. If the circuit breaker of the substation trips due to the fault current flowing in the distribution line L within the time when this short circuit detection signal is input, the distribution line L becomes a no-voltage state, so the zero-phase voltage determination circuit 46 The output of is no voltage.

Then, the no-voltage detection circuit 48 detects that the output signal is no voltage from the zero-phase voltage determination circuit 46, as in the case of the ground fault, and detects no voltage corresponding to the logical value 1 to the AND circuit 44. Output a signal. As a result, the AND circuit 4
Reference numeral 4 inputs both the no-voltage detection signal corresponding to the logic value 1 and the short circuit detection signal, and outputs the short circuit display drive current corresponding to the logic value 1. As a result, the short-circuit indicator 45 displays a short-circuit.

In this embodiment, it is not necessary to connect a cable or the like between the detectors A, B, and C for signal transmission, so there is no concern about insulation deterioration between different phases.

Next, a second embodiment will be described with reference to FIG.

In the above-described embodiment, the voltage value signal and the current value signal detected by the first and second detectors A and B are transmitted by space propagation, but in this embodiment, the current value signals of the detectors A and B are used instead. The different point is that the light emitting element 28 for voltage and the light receiving element 29 for voltage value signal are connected by optical fibers 51, 52, and each signal is transmitted by these optical fibers 51, 52.

In this embodiment, the different phases are connected by the optical fibers 51 and 52, so that the signal can be surely transmitted.

Other functions and effects are similar to those of the above embodiment.

EFFECTS OF THE INVENTION As described in detail above, in the fault current detection device of the present invention, the sensor attached to each phase detects the fault current flowing in the distribution line by using light, so that it interferes with electromagnetic induction. In other words, since the insulation is high, the electrical reliability can be improved.

Furthermore, it does not require a grounding transformer and has a simple structure of a current level determination circuit, a short circuit detection circuit, a zero-phase current determination circuit, a zero-phase voltage determination circuit, and a phase determination circuit. In addition, the cost can be reduced, and by installing it on the distribution line, it is possible to detect from the installation point whether the ground fault accident point is the power supply side or the load side. This fault current detection indicator By arranging a large number of wires on the distribution line, this has a great effect on shortening the failure point search time and, in turn, on early recovery, and also on the short-circuit display.

Further, according to the present invention, the output signal from each sensor is only transmitted to the detector provided in the intermediate phase of the distribution line, and the wiring between the phases of the control line is not necessary. Noise will not be picked up on the control line as compared with the case of turning. Therefore, the reliability can be increased.

Also, since various signals are sent from the detectors provided in the two phases in addition to the detectors provided in the intermediate phase, for example, the signals from the detectors provided in the other two phases are sent to the detectors provided in other than the intermediate phase. Even when there is a signal loss, the loss of signals from the other two phases can be made equal as compared with the case of transmitting. Therefore, in the present invention, the output adjustment of the signal in the other two-phase detectors provided other than the intermediate phase and the input adjustment of the detector on the intermediate phase side can be performed in the same way in consideration of the loss of the signal. .

[Brief description of drawings]

FIG. 1 is a perspective view of a fault current detection indicator attached to a distribution line according to an embodiment of the present invention, FIG. 2 is a bottom view of a display portion of the fault current detection indicator, and FIG. FIG. 4 is an electric circuit diagram of another detector, FIG. 5 is an electric circuit diagram of a power supply circuit, FIG. 6 is a principle diagram of a current sensor, FIG. 7 is a principle diagram of a voltage sensor, FIG. 8 shows a diagram of the polarization state of light, (a) is an explanatory view of random polarization,
(B) is an explanatory diagram of linearly polarized light, (c) is an explanatory diagram of linearly polarized light rotated by a rotation angle φ, (d) is an explanatory diagram of circularly polarized light, (e) is an explanatory diagram of elliptically polarized light, and FIG. It is a perspective view of the state which attached to the distribution line of the fault current detection indicator of 2 examples. 1 ... Fault current detection indicator, 2 ... Optical fiber current sensor,
3 ... Faraday element, 4 ... Polarizer, 5 ... Analyzer, 10 ...
First light emission drive circuit, 11, 12 ... Photosensor element for current sensor, 13 ... Current value signal processing circuit, 14 ... Optical fiber voltage sensor, 15 ... Pockels element, 16 ... λ / 4 plate, 17
... Polarizer, 18 ... Analyzer, 23, 24 ... Light receiving element for voltage sensor, 25 ... Voltage value signal processing circuit, 26 ... Transmission circuit,
27 ... Second light emitting element drive circuit, 28 ... Current value signal light emitting element, 29 ... Voltage value signal light emitting element, 33 ... Current value signal light receiving element, 35 ... Voltage value signal light receiving element, 37, 3
8, 39 ... Current level determination circuit, 40 ... Short circuit detection circuit,
41 ... Amplifier, 42 ... Zero-phase current judging circuit, 43 ... Phase judging circuit, 44 ... AND circuit, 45 ... Short-circuit indicator, 46 ...
Zero-phase voltage discrimination circuit, 47 ... Display direction selection circuit, 48 ... No-voltage detection circuit, 49 ... Ground fault direction indicator, L ... Distribution line, A
... first detector, B ... second detector, C ... third detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsunori Aoki No. 1 Kamikomenee, Inuyama City, Aichi Prefecture Takamatsu Denki Seisakusho Co., Ltd. (72) No. 1 Yasuhiro Tanahashi, Inouyama City, Aichi Prefecture Takamatsu Co., Ltd. Electric Manufacturing (56) Reference JP-A-57-85525 (JP, A) JP-A-58-208672 (JP, A) JP-A-60-253880 (JP, A)

Claims (1)

[Claims] 1. A detector for each phase is suspended from and supported on a distribution line of each phase, and the detector of each phase uses the change in the magnetic field generated in the distribution line of the corresponding phase to flow to the distribution line. An optical fiber current sensor that detects an electric current and outputs an optical signal based on the change in the magnetic field, and detects the voltage of the distribution line by utilizing the change in the electric field that occurs in the distribution line of the corresponding phase, and detects the change in the electric field. And an optical fiber voltage sensor that outputs an optical signal based on the optical fiber voltage sensor. The detector provided in the intermediate phase of the distribution line further converts the optical signal output from the optical fiber current sensor of each phase into an electrical signal. First photoelectric conversion means, second photoelectric conversion means for converting the optical signal output from the optical fiber voltage sensor of each phase into an electric signal, and the phase current based on the signal from the first photoelectric conversion means Is short circuit current level when short circuit is detected A zero-phase current discriminating means for detecting a zero-phase current based on a signal from the first photoelectric conversion means of each phase and discriminating the phase of the zero-phase current, and a second photoelectric cell of each phase. Zero phase voltage determining means for detecting a zero phase voltage based on a signal from the converting means and performing phase determination of the zero phase voltage, a phase determination result of the zero phase current determining means and a phase determination result of the zero phase voltage determining means. Based on the results of the determination of both, the phase determination means that outputs a determination signal whether the ground fault point is either the power supply side or the load side, and a no-voltage detection means that detects the no-voltage state of the distribution line, Short circuit detection of the short circuit detection means, short circuit display output means for outputting a short circuit display signal based on the detection of no voltage of the no-voltage detection means, determination of the phase determination means, detection of no voltage of the no-voltage detection means A ground fault direction table that outputs a direction display signal based on A short-circuit indicator for displaying a short circuit in response to a display signal from the output means and a short-circuit display output means, and a ground fault for displaying a directional ground fault in response to a display signal from the ground fault directional display output means. A fault current detection display device, which is provided with a direction indicator.