JPS61202172A - Faulty current detector/display unit - Google Patents

Abstract

PURPOSE:To achieve a quick detection of ground-fault accident while simplifying the construction of a detector/display unit without being obstracted by electromagnetic induction, by transmitting a optical signal based on the changes in the magnetic field and electric field of a wiring to compute. CONSTITUTION:A wiring L is provided with a detector C and a fault current detector/display unit 1 having detectors A and B of the same construction. The detectors A and B have a detecting section and a light transmitting section and an optical fiber current sensor comprising a Faraday effect element and an optical fiber voltage sensor comprising a Pockels effect element are arranged on a case of the detector close to the wiring L. Current and voltage outputs of sensors are converted into optical signals to be transmitted to light receiving elements 33 and 35 of the detector C from light emitting elements 28 and 29. The detector C performs a computation based on the received signal and a zero-phase current to decide on a ground-fault phenomenon and the short- circuiting is shown on a display 45 while ground-fault directions on displays 49a and 49b.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention provides a fault current detection and display device that displays a short circuit or ground fault when a short circuit or ground fault occurs in a distribution line. This is Seki J Ruchino.

(Prior art) Conventionally, when a ground fault occurs in a distribution line, from the viewpoint of early detection of a small number of sections, isolation of the faulty section, and early transmission of power to the entire R section, the first step is to open the substation circuit breaker, and then At the same time, the substation circuit breaker is reclosed, and power is retransmitted to the healthy section by sequentially turning on the sectional switches on the power supply side, and the substation circuit breaker is shut off again when the faulty section reaches the ground fault section.

When the circuit breaker of the substation is closed again, the section switch that separates the ground fault fault section is locked in the open state, and only the ground fault fault section is isolated, and power is retransmitted only to the healthy section. , searching for ground fault sections. Once a ground fault fault section has been found, the ground fault point is detected by repeatedly measuring the insulation resistance of the related power distribution equipment installed on each utility pole in the fault section.

(1-Problem to be Solved by the Invention) As mentioned above, in the past, after the ground fault fault section was identified, the related power distribution equipment installed on the utility poles, etc. existing in the ground fault fault section was sequentially installed for each utility pole. Since insulation resistance measurements were being carried out, there was a problem with the work in that it took a lot of time, and it took a long time to detect ground faults.

(Means for Solving the Problems) It is an object of the present invention to solve the above-mentioned problems and to provide a fault current detection display device that has superior insulation performance compared to conventional ground fault display devices.

That is, the fault current detection and display device of the present invention is placed close to the distribution line of each phase, detects the current flowing through the distribution line using changes in the magnetic field generated in the distribution line, and generates an optical signal based on the change in the magnetic field. An optical fiber current sensor that outputs, a current sensor light receiving element that converts the optical signal output from the optical fiber current sensor into an electrical signal, and a current that flows through the distribution line based on the electrical signal from the current sensor light receiving element. A current value signal processing circuit that calculates the current value of and outputs a current value signal, and a current value signal processing circuit that is also placed close to the distribution line of each phase and detects the voltage of the distribution line using changes in the electric field that occur in the distribution line. an optical fiber voltage sensor that outputs an optical signal based on a change in the electric field; a voltage sensor photodetector that converts the optical signal output from the optical fiber voltage sensor into an electric signal; and a voltage sensor photodetector that outputs an optical signal based on a change in the electric field; A voltage value signal processing circuit that calculates the voltage value of a distribution line based on an electric signal, and a current level judgment that determines whether the current value level is a predetermined current value level based on the current value signal from the current value signal processing circuit. circuit, and a short circuit in which when the current level determination circuit determines that the current value is a predetermined level or higher, the current value signal is inputted, and when the current value is at the short circuit current value level, the short circuit current is detected and a short circuit detection signal is output. a detection circuit; and a zero-sequence current discrimination circuit that detects a zero-sequence current based on the current value signal of each phase output from the current level judgment circuit when the current level is not at a predetermined level, and outputs a phase signal of the zero-sequence current. , a zero-phase voltage discrimination circuit that detects a zero-phase voltage based on the voltage value signal from the voltage value signal processing circuit of each phase and outputs a phase signal of the zero-phase voltage, and a phase signal from the zero-phase current discrimination circuit. and the phase signal from the zero-sequence voltage discrimination circuit.The phase determination circuit compares the phases of the ground fault and the phase signal from the zero-sequence voltage determination circuit, and outputs a determination signal as to whether the ground fault fault point is on the power supply side or the load side based on the phase comparison.
a no-voltage detection circuit that detects a no-voltage state of a distribution line when a substation circuit breaker trips due to current and outputs a no-voltage detection signal; a short-circuit detection signal output from the short-circuit detection circuit; and a no-voltage detection circuit that outputs a no-voltage detection signal; A first AND circuit that inputs the no-voltage detection signal from the detection circuit as a signal corresponding to a logical value of 1 and outputs a short-circuit display drive current, and a first AND circuit that outputs a short-circuit display drive current and determines which one is output from the phase determination circuit. a second AND circuit which inputs the signal and the no-voltage detection signal from the no-voltage detection circuit as signals corresponding to a logic value 1, and outputs a directional display drive current; A short circuit indicator that displays a short circuit in response to a short circuit display drive current from the circuit; and a ground fault direction indicator that displays a directional ground fault in response to a directional display drive current from the second AND circuit. Its gist is that it has been constructed with a vessel.

(Function) According to the above configuration, when a ground fault occurs, the optical fiber current sensor of each phase detects the fault current flowing in the distribution line based on the change in the magnetic field of the distribution line, and generates an optical signal based on the change in the magnetic field. Output. Then, the current sensor light receiving element converts the optical signal output from the optical fiber current lens into an electrical signal,
The current value signal processing circuit calculates the current value of the current flowing through the distribution line based on the electrical signal from the current light receiving element and outputs a current value signal.

The current level determination circuit determines whether the current value level is a predetermined current value level based on the current value signal from the current value signal processing circuit. If the current determining circuit determines that the current level is not at the predetermined level, the zero-sequence current determining circuit detects the zero-sequence current based on the current value signal of each phase output from the current level determining circuit. Outputs phase signal.

On the other hand, an optical fiber voltage sensor detects the voltage of a power distribution line using changes in the electric field occurring in the power distribution line, and outputs an optical signal based on the change in the electric field. The voltage light receiving element converts the optical signal output from the optical fiber voltage sensor into an electrical signal, and the voltage value signal processing circuit calculates the voltage value of the distribution line based on the electrical signal from the voltage sensor light receiving element.

The zero-phase voltage discrimination circuit detects the zero-phase voltage based on the voltage value signal from the voltage value signal processing circuit of each phase, and outputs a phase signal of the zero-phase voltage. Then, the phase determination circuit compares the phase signal from the zero-sequence current determination circuit (E and the phase signal from the zero-phase voltage determination circuit), and determines whether the ground fault point is on the power supply side or the load side based on the phase comparison. A determination signal for one of the two is output.

When the substation circuit breaker trips due to fault current, the no-voltage detection circuit detects the no-voltage state of the distribution line,
Outputs a no-voltage detection signal. A second AND circuit receives one of the determination signals output from the phase determination circuit,
The no-voltage detection signal from the no-voltage detection circuit is input as a signal corresponding to a logical value of 1, and a directional display drive current is output. Then, the ground fault direction indicator displays a directional ground fault by the directional display drive current from the second AND circuit.

In addition, when a short circuit accident occurs, the optical fiber current sensor of each phase operates to detect based on the change in the magnetic field of the distribution line, as in the case of the ground fault accident, and the current sensor light receiving element and current value signal processing circuit Based on the current value signal, the current level determination circuit determines that the current value level is equal to or higher than a predetermined level. Then, the short-circuit detection circuit inputs the current value signal, and when it reaches the short-circuit current value level, detects the short-circuit current and outputs a short-circuit detection signal.

When the substation circuit breaker trips due to fault current, the no-voltage detection circuit detects the no-voltage state of the distribution line,
Outputs and covers the no-voltage detection signal. When the first AND circuit receives the short-circuit detection signal and the no-voltage detection signal from the no-voltage detection circuit as signals corresponding to a logical value of 1, it outputs a short-circuit display drive current. As a result, the short circuit indicator displays a short circuit in response to the short circuit display drive current from the first AND circuit.

(Example) An example embodying this invention' is shown in Figs. 1 to 8 below.
This will be explained according to the diagram.

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

Since the first and second detectors A and B have the same configuration, the first detector A can be roughly divided into a detection section α, a transmission section 26, and a power supply section 32. has been done.

The detection unit α will be explained.

An optical fiber current sensor 2 (hereinafter referred to as a current sensor) is arranged on the upper part of the case of the detector A so as to be close to the power distribution line. This current sensor 2 has a polarizer 4 disposed on one end side of a Faraday element 3 which has a magneto-optical effect (particularly the Faraday effect; when linearly polarized light is passed along the direction of a magnetic field, its plane of polarization rotates). An analyzer 5 tilted at an angle of π/4 with respect to the polarizer 4 is arranged on the other end side. The Faraday probe 3 is made of bismuth silicon oxynide (Bi 128), which has a large Verdet constant.
i 020), rare earth iron garnet (Y3Fe5O
12) etc. are used.

One end of an optical fiber 6 for transmitting incident light is disposed relative to the polarizer 4. A light emitting element 9 made of a light emitting diode is connected to the other end of the optical fiber 6 of the current range 2. A first light-emitting element drive circuit 10 is connected to the light-emitting element 9, and the second light-emitting element drive circuit 10 always drives a certain amount of randomly polarized light (see FIG. 8(a)). It has become.

Therefore, this current sensor 2 converts the randomly polarized light incident through the optical fiber 6 into linearly polarized light (see FIG. 8).
When linearly polarized light passes along the direction of the magnetic field, the Faraday element 3 rotates the plane of polarization of the linearly polarized light by an angle φ (see Figure 8 (C)) in proportion to the change in the magnetic field. reference)
Rotate. Further, the analyzer 4 converts the emitted light tilted by the rotation angle φ at the Faraday element 3 into a light amount change component P1 and a light amount change component P2.

Furthermore, one end of an optical fiber 7.8 is arranged relative to the analyzer 5, respectively. At the other end of the optical fiber 7.8 is a current sensor light receiving element 11.12 consisting of a photodiode.
is connected. Light receiving element 11.12 for the same current sensor
is the X-axis direction component P1 incident from the optical fiber 7°8
The amount of light in the y-axis direction component P2 is converted into an electrical signal, and the electrical signal is output to the current value signal processing circuit 13.

The current value signal processing circuit 13 combines both input electric signals to calculate the rotation angle φ, and further calculates a current value proportional to the magnetic field H.

The current value signal processing circuit 13 outputs a current value signal Sj1 corresponding to the obtained current value to a transmission circuit 26 to be described later.

Similar to the current range 2, an optical fiber electric sensor 14 (hereinafter referred to as a voltage sensor) is provided close to the power distribution line with respect to the detector 1.

The lightning pressure sensor 14 is connected to one end of a Pockels element 15 which has an electro-optic effect (particularly the Pockels effect; a property in which the refractive index for light waves with electric fields in the X and Y directions changes in proportion to the applied voltage). is a λ/4 plate (λ; wavelength) 16
A polarizer 17 is disposed through the polarizer 17, and an analyzer 18 is disposed at the other end.

The Pockels element 15 is made of, for example, bismuth silicon oxide (B i 128 i 020), m
B i 2Ge 1 (B i 2Ge 3012) and the like are used.

One end of an optical fiber for transmitting incident light is disposed relative to the polarizer 17 . A light emitting element 20 consisting of 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 -th light emitting element drive circuit 10 normally outputs IL'! It is designed to emit constant random polarized light (see FIG. 8(a)).

Therefore, in this voltage sensor 14, the polarizer 17 converts the random polarized light incident through the optical fiber 20 into linearly polarized light, and the λ/4 plate 16 is operated at an angle of 90 degrees to the linearly polarized light having electric fields in the x and y directions. Circularly polarized light (8th
(d) (see figure). Furthermore, Pockels element 1
5 is the electro-optic effect (X in proportion to the applied voltage,
(The property that the refractive index changes for light waves with an electric field in the y direction) converts incident circularly polarized light into elliptically polarized light (Figure 8 (
(see e)). The analyzer 18 converts the elliptically polarized light output from the Pockels element 15 into an x-axis component Q1 and a y-axis component Q2.

Further, one ends of optical fibers 21 and 22 are disposed relative to the analyzer 18, respectively, and a voltage sensor light receiving element 23.
24 are connected. Light receiving element 23 for the same voltage sensor.
24 converts the amount of light of the X-axis direction component Q1 and the y-axis direction component Q2 incident from the optical fibers 21 and 22 into electrical signals, and outputs the electrical signals to the voltage value signal processing circuit 25.

The voltage value signal processing circuit 25 combines both input electric signals to calculate an electric field E, and further calculates a voltage value flowing to the distribution line 1- based on the electric field F. Then, the voltage value signal processing circuit 25 outputs a current value signal SV1 corresponding to the obtained voltage value to a transmission circuit 26 to be described later.

Said current sensor2. Voltage sensor 1/I, first light emitting element drive circuit 10X current value signal processing circuit 13, voltage value signal processing circuit 25, light emitting cables 9, 20, light receiving elements 11, 12 for current sensing, light receiving for voltage sensor The detection section α is composed of elements 23.2=1, etc.

The transmission circuit 26 as a transmission section includes a second light emitting element drive circuit 27 and a pair of current value signal light emitting elements, each of which is connected to the second light emitting element drive circuit 27 and includes a light emitting diode or the like that emits visible light or infrared light. 28 and a voltage value signal light emitting element 29. Each of the light emitting elements 28 and 29 is exposed to the side of the case of the first detector A so as to correspond to the light receiving elements 33 and 35 for current value signal and voltage value of the third detector C described later. (See Figure 1). and,
The second light emitting element drive circuit 27 receives the current value signal Sj 1
．． and the light emitting elements 28 and 29 based on the voltage value signal Sv1.
They are designed to each drive light emission.

In FIG. 5, a current transformer CT attached to the distribution line is provided on 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. There is. And the positive of the rectifier circuit 30.

Between both negative terminals are a resistor R1, the collector/emitter of a transistor Tr, a resistor R2, and a rechargeable battery 3.
1 series circuit is connected. 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 7D is connected between the base terminal of the transistor Tr and the negative terminal of the rectifier circuit 30.

The rectifier circuit 30. Resistor R1, transistor Tr, resistor R2, battery 31. Resistor R3, Zener diode Z
D constitutes a power supply circuit 32 as a power supply section. 1. The power supply circuit 32 supplies drive current to each circuit. r -) 'r is there.

Note that the current value signal light emitting element 28 and the voltage value signal light emitting element 29 of the second detector B output a current value signal Sj2 and a voltage value signal Sv2 as in the first detector A and the like.

Next, the third detector C will be explained according to FIG.

In this third detector C, the same components as those of the first and second detectors A and B are designated by the same reference numerals τ1 for convenience of explanation.

This third current detector C includes a detection section α having the same configuration as the first and second detectors A and B attached to the other two phases. The voltage value signal processing circuit 13 and the voltage value signal processing circuit 25 of the third detector C output a current value signal Sj3 and a voltage value signal SV3.

On the side of the case of the third detector C are a light emitting element 28 for current value signal and a light emitting element 29 for voltage value signal of the first detector Δ.
Corresponding to this, a current value signal light receiving element 33 and a voltage value signal light receiving element 35 are respectively exposed and arranged. or,
On the other side of the case of the third detector C are the i-optical element 28 for current value signal and the light emitting element 29 for voltage value signal of the second detector B.
Corresponding to this, a current value signal light receiving element 34 and a voltage value signal light receiving element 36 are respectively exposed and arranged.

The current value signal light receiving elements 33, 34 and the voltage value signal light receiving elements 35, 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. The optical signal from the element 29 is input (received), and based on the optical signal, the current value signal Sj1. Sj2 and voltage value signal SV1. They are each converted and output to S2.

A first and second current level determination circuit 37.38 is connected to the current value signal light receiving element 33.34, respectively,
Further, 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 ゛I'11 constant circuit 37゜38.39 receives the input current value Gi Sj1゜S, f2. Each detector detects whether the current level flowing through Sj3 is at a predetermined level.

A common short circuit detection circuit/IO is connected to one output terminal of each current level determination circuit 37, 38, 39, and an amplifier 41 is connected to the other output terminal. The output terminals of each amplifier 41 are connected to each other to form a zero-sequence current discrimination circuit 42.
A phase determination circuit 43, which will be described later, is connected to. Note that a resistor R4 is connected between the input and output terminals of the amplifier 41.

The common fault detection circuit 40 is connected to the current level determination circuit 37.3.
8.39 is detected to be above a predetermined level, and if the level is the short-circuit current value level, a short-circuit detection signal is output. On the other hand, if the current level determination circuits 37, 38, and 39 determine that the current level is below the predetermined level, the signal is amplified by the amplifier 41, and the zero-sequence current determination circuit 42 determines the zero-sequence current based on the signal. detect,
The phase signal of the zero-phase current is output to the phase determination circuit 43.

The output terminal of the short circuit detection circuit 40 has a first AND circuit/1
．． 4 is connected, and the negative AND circuit 44 receives the short circuit detection signal as a signal corresponding to the logic value 1. A short circuit indicator 45 is connected to the output terminal of the first AND circuit 44, and when a no-voltage detection signal corresponding to a logic value 1 (to be described later) and the short circuit detection signal are both inputted, a short circuit display corresponding to a logic value 1 is displayed. The short circuit indicator 45 is configured to display a short circuit by outputting a drive current.

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

The voltage value signal optical element 35, 36 and the third detector C
The voltage value signal processing circuit 25 is connected to the phase determination circuit 43 via a star-connected zero-phase voltage determination circuit 46 via resistors R5 to R7.

Therefore, the three-phase voltage value signals SV1. The zero-phase voltage is detected based on the voltage value signal SV3 for one phase from the voltage value signal processing circuit 25 of the SV2 and the third detector C, and the phase signal of the zero-phase voltage is output to the phase determination circuit 43. It looks like this.

The phase determination circuit 43 compares the phase of the phase signal from the zero-sequence current determination circuit 42 and the phase signal from the zero-phase voltage determination circuit 46, and determines whether the ground fault point is on the power supply side of the display device based on the phase comparison. It is designed to output a judgment signal for either the load side or the load side.

In other words, if the phase of the zero-sequence current is close to leading by 0 to 110 degrees with respect to the phase of the zero-sequence voltage, it is assumed that the ground fault fault point is on the load side, and a load-side judgment signal is output, and the opposite When the phase of the zero-sequence current is shifted by 180 degrees, it is assumed that the ground fault point is on the power supply side, and a power supply side determination signal is output. A second AND circuit 47 is connected to the output terminal of the phase determination circuit 43.

Further, a no-voltage detection circuit 48 is connected to the output side of the zero-phase voltage discrimination circuit 46, and its output terminal is connected to the first AND circuit 44 and the second AND circuit 47.

This no-voltage detection circuit 48 is a zero-phase voltage discrimination circuit 46. When it is detected that the output signal from the
It is designed to output a no-voltage detection signal corresponding to.

Said second AND circuit 1! I7 has a ground fault direction indicator 49 connected to its output terminal, and when the no-voltage detection signal corresponding to the logical value 1 and the judgment signal from either the power supply side or the load side are input together, the judgment signal Based on the logical value 1, a power supply side direction display drive current or a load side direction display drive current corresponding to the logical value 1 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 located on the power supply side display section 49a.
and a load side display section 49b are provided, and when a power supply side determination signal is input to the second AND circuit 47, the power supply side display section 16a displays the direction to the power supply side, and the load side display drive current When input, the load side display section 16b displays the load side direction.

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

When a steady load current is flowing through the distribution line, the first, second and third detectors A, 13.C installed in each phase are
In the power supply circuit 32, a certain amount of transformed current is outputted from the current transformer CT, and the transformed current is rectified by the rectifier circuit 30 to charge the battery 31.

(Now, if a ground fault occurs in one of the distribution lines and a fault current flows through the distribution line, the detectors A, B, and C of each phase will
Current sensor 2 detects the fault current. That is, in the current sensor 2, the photoconductor 4 converts the randomly polarized light incident 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 field. Rir.

Roughly speaking, the analyzer 4 has a rotation angle φ at the Faraday probe 3.
The tilted emitted light is converted into a light amount change component P1 and a light-♀ change component P2.

The current sensor light receiving element 11.12 converts the light amount of the light amount change component P1 and the light amount change component P2 incident from the optical fiber 7.8 into an electric signal, and outputs the electric signal to the current value signal processing circuit 13. do. The current value signal processing circuit 13 combines both input 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 transmits a current value signal 5j1 (current value signal Sj 2 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. Output.

The second light emitting element drive circuit 27 receives the current value signal Sjl,
The light emitting elements 28 and 29 are each driven to emit light based on the voltage value signal SVI. This current value signal light receiving element 33
inputs (receives) the optical signal from the current value signal light emitting element 28 of the first detector A and the third detector C, respectively, and receives the current value signal 5j1 (second detector) based on the optical signal. B
In each case, the current value signal Sj2) is converted and output.

Each of the current I novel determination circuits 37, 38, and 39 receives the input current value signal Sj1. Sj 2. It is detected whether the current level based on Sj3 is at a predetermined level or not, and when the current level determination circuit 37゜38.39 determines that it is below the predetermined level, the signal is amplified by the amplifier 41 and the zero-sequence current The discrimination circuit 42 detects a zero-sequence current based on the signal, and outputs a phase signal of the zero-sequence current to the phase determination circuit 43.

On the other hand, when the fault current flows through the distribution line, 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 sensors 4 and 14 of each detector A, B, and C convert the randomly polarized light incident on the polarizer 17 through the optical fiber 20 into linearly polarized light, and the λ/4 plate 1G converts it into linearly polarized light in the X and y directions. An optical phase difference of 90° is given to the same linearly polarized light having an electric field, and the light is converted one fan ahead of the circle. Roughly speaking, the Pockels element 15 has an electro-optic effect (X in proportion to the applied voltage).
, the property that the refractive index changes with respect to a light wave having an electric field in the y direction) causes the incident circularly polarized light to become elliptically polarized light. Then, =26- 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 amounts of light of the X-axis direction component Q1 and the y-axis direction component Q2 incident through the optical fibers 21 and 22 into electric signals, and convert the electric signals into voltage value signal processing circuits. Output to 25. The same voltage value signal processing circuit 25 combines both input electric signals to calculate the electric field E, and roughly based on the electric field E calculates the voltage value of the distribution line [.

Then, the voltage value signal processing circuit 25 generates a current value signal SV1. corresponding to the obtained voltage value. SV2 is output to the transmission circuit 26.

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

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

The zero-phase voltage discrimination circuit 46 includes a voltage value signal light receiving element 35.3.
The three-phase voltage value signal SV1. The zero-phase voltage is detected based on the voltage value signal SV3 for one phase from the voltage value signal processing circuit 25 of the third detector C such as SV2, and the phase signal of each zero-phase voltage is output to the phase determination circuit 43. do.

The phase determination circuit 43 performs a phase comparison between the phase signal from the zero-phase current determination circuit 42 and the phase signal from the zero-phase voltage determination circuit 46.

At this time, if the phase of the zero-sequence current is close to leading by 0 to 110 degrees with respect to the phase of the zero-sequence voltage as a reference, it is determined that the ground fault point is on the load side, and a load-side determination signal is output. On the other hand, when the phase of the zero-phase current is 180 degrees out of phase, it is assumed that the ground fault point is on the power supply side, and a power supply side determination signal is output to the second AND circuit 47.

If the circuit breaker of the substation trips by one helibut due to the fault current flowing through the distribution line while the power supply side or load side determination signal is being output to the second AND circuit 47, the distribution line becomes voltageless. state, the zero-phase voltage discrimination circuit 4
The output from 6 is a no-voltage roar.

Then, the no-voltage/detection circuit 48 becomes the zero-phase voltage discrimination circuit 46.
It is detected that the output signal from the output signal is no voltage, and a no-voltage detection signal corresponding to the logical value 1 is outputted to the second AND circuit 47. As a result, the AND circuit 47 outputs the logical value 1.
Input the non-voltage detection 7J+ signal corresponding to the power supply side or the load side judgment signal together, and based on the judgment signal, the power supply side direction display drive current or load side direction display corresponding to the logical value 1 is input. Outputs drive current.

Then, the ground fault direction indicator 49 displays the power supply side display section 49a or the load side display section 49b by this display drive current. Therefore, the power supply side or load side display parts 49a and 49b of the ground fault direction indicator on the bottom surface of the third detector C display the directionality. ! A person visually confirms the display and determines whether the ground fault point is on the power supply side or the load side from the fq point where the fault current detection display device 1 is installed.

In addition, if a short circuit occurs in the distribution line and a fault current (i.e., 0-fault current) flows, each detector A, B, . . .
The sensor 2 detects the current of C, and in the third detector C, each current level determination circuit 37, 38, 39 receives the input current value signal Sjl.

Sj2. It is determined whether the current level based on Sj3 is a predetermined level.

The short circuit detection circuit 40 is the current level determination circuit 37.3.
8.39 is a predetermined level or higher, and if that level is the short circuit current value level, a short circuit detection signal is output.

Then, the first 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 through the distribution line during the time when this short circuit detection signal is being input, the distribution line will be in a no-voltage state, so that the zero-phase voltage determination circuit 46 The output is a no-voltage roar.

Then, the no-voltage detection circuit 48 detects that the output signal from the zero-phase voltage discrimination circuit 46 is no-voltage, as in the case of the ground fault, and sets the logic value 1 to the first AND circuit 44.
Outputs the corresponding no-voltage detection signal. As a result, the first AND circuit 44 receives 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, since there is no need to connect cables or the like between the detectors A, B, and C for signal transmission, there is no need to worry about insulation deterioration between different phases.

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

In the above embodiment, the voltage value signal and the current value signal detected by the first and second detectors A and B were propagated in space, but in this embodiment, the current of the detectors A and B is used instead. The difference is that the value signal light emitting element 28 and the voltage value signal light receiving cable 29 are connected by optical fibers 51 and 52, and each signal is transmitted through the optical fibers 51 and 52.

In this embodiment, since different phases are connected by optical fibers 51 and 52, signal transmission can be performed reliably.

Other effects are the same as in the previous embodiment.

The third embodiment will be briefly described with reference to FIGS. 10 and 11.

In this embodiment, unlike the first embodiment, each detector A,
B and C are configured with only the current sensor 2 and voltage sensor 14, and a control circuit box 53 is attached to the utility pole P. The first light emitting element driving circuit 10, the light emitting elements 9, 20 are housed in the control circuit box 53, and the current level determining circuits 37, 38, 39, short circuit detection circuit 40, amplifier 41, zero phase Current determination circuit 42, phase determination circuit 43, first AND circuit 44, second AND circuit 4
7. A no-voltage detection circuit 48 is housed, and a short circuit indicator 45 and a ground fault direction indicator 49 are exposed on the front surface of the control circuit box 53.

Then, from the control circuit box 53, the light emitting elements 9,
An optical fiber 6.19 for each reno 4 connected to 20 extends to each of said detectors A, B, C. Roughly speaking, optical fibers 7.8, 21, 2 extend from the sensors 2, 14 to each detector A, B, C.

2 is connected to the current value signal processing circuit 13 and voltage value signal processing circuit 25 provided for each phase in the control circuit box 53 through the current sensor light receiving element 11.12 and the voltage sensor light receiving element 23.24, respectively. It is connected. Further, each current value signal processing circuit 13 and voltage value signal processing circuit 25 is a current level determination circuit 37, 38, 39, respectively.
The difference is that they are connected to the zero-phase voltage discrimination circuit 46.

In this embodiment, the power supply unit 54 that drives each circuit in the control circuit box 53 uses the secondary side of a PT or the load side of a transformer provided in a conventionally known fault section detection device. .

In this embodiment, the optical signal and electrical signal only need to be converted once, resulting in less signal loss and higher reliability. Furthermore, a detector A is attached to the power distribution line.

Since B and C are configured with only sensors 2 and 14, it is possible to replace them with extremely small and light weight detectors A, B and C.

Effects of the Invention (Details above) Since it is not disturbed by electromagnetic induction and is highly insulated, the electrical reliability 11 can be increased.

Furthermore, there is no need for a grounding transformer, and a simple configuration consisting of a current level judgment circuit, short circuit detection circuit, zero-sequence current judgment circuit, zero-sequence voltage judgment circuit, and phase judgment circuit is sufficient, making the entire device smaller and lighter. and can reduce costs,
Roughly speaking, by attaching it to the distribution line (=jE), it is possible to detect whether the ground fault point is on the power supply side or the load side from the attachment point with a simple configuration. If a large number of them are placed in the area, it will be very effective in shortening the time it takes to find a fault point and thus speed up recovery, and it will also have the excellent effect of indicating a short circuit.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a fault current detection indicator according to an embodiment of the present invention attached to a power distribution line, FIG. 2 is a bottom view of the display section of the fault current detection indicator, and FIG. The electric circuit diagram of the detector, Figure 4 is the electric circuit diagram of other detectors, Figure 5 is the electric circuit diagram of the power supply circuit, and Figure 6 is the principle of the current sensor.
¥1, Figure 7 shows the original raccoon diagram of a voltage sensor, Figure 8 shows a diagram of the polarization state of light, (a) is an illustration of random polarization, (b) is an illustration of linear polarization, ( C) An explanatory diagram of 1 unit linearly polarized light rotated by the rotation angle φ, (d) is an explanatory diagram of circularly polarized light,
(e) is an explanatory diagram of elliptically polarized light, FIG. 9 is a perspective view of the fault current detection indicator of the second embodiment installed on a distribution line,
FIG. 0 is a perspective view of the third practical example of the fault current detection and display device in which the detector is attached to the power distribution line, and FIG. 11 is its electric circuit diagram. DESCRIPTION OF SYMBOLS 1... Fault current detection indicator, 2... Optical fiber current sensor-13... Faraday element, 4... Polarizer,
5... Analyzer, 10... First light emission drive circuit, 11
．． 12... Light receiving element for current sensor, 13... Current value signal processor]! 11 circuit, 14...optical fiber voltage lens 4
1.15...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...Light emitting element for park signal, two ...
Light emitting element for voltage value signal, 33... Light receiving element for current value signal, 35... Light receiving element for electric fffri'+ signal, 37
, 38.39...Current level determination circuit, 40...Short circuit detection circuit, 41...Amplifier, 42...Zero-phase current discrimination circuit, 43...Phase determination circuit, 44...First AND circuit, 45... Short circuit indicator, 46... Zero phase voltage discrimination circuit, 17... Second AND circuit, 48... No voltage detection circuit, 49... Earth fault direction indicator , 1-...
Distribution line, A...first detector, B...second detector, C...third detector. Patent applicant Ne1 Co., Ltd. Takamatsu Electric Mfg. Co., Ltd. Representative
Person Patent Attorney On 1) Bo Yipeng■ Taste

Claims (1)

[Claims] 1. A device that is placed close to the distribution line of each phase, detects the current flowing through the distribution line by using changes in the magnetic field generated in the distribution line, and outputs an optical signal based on the change in the magnetic field. an optical fiber current sensor; a current sensor light receiving element that converts an optical signal output from the optical fiber current sensor into an electrical signal; and a current value of a current flowing through a distribution line based on the electrical signal from the current sensor light receiving element. A current value signal processing circuit that calculates the current value and outputs a current value signal, and a current value signal processing circuit that is also placed close to the distribution line of each phase and detects the voltage of the distribution line using changes in the electric field that occur in the distribution line, and an optical fiber voltage sensor that outputs an optical signal based on a change; a voltage sensor light receiving element that converts the optical signal output from the optical fiber voltage sensor into an electrical signal; a voltage value signal processing circuit that calculates the voltage value of the distribution line; a current level determination circuit that determines whether the current value level is a predetermined current value level based on the current value signal from the current value signal processing circuit; a short circuit detection circuit that inputs a current value signal when the current level determination circuit determines that the current value is a predetermined level or higher, and that detects a short circuit current and outputs a short circuit detection signal when the current level is at a short circuit current value level; a zero-sequence current discrimination circuit that detects a zero-sequence current based on the current value signal of each phase outputted from the current level judgment circuit when the current level is not at a predetermined level, and outputs a phase signal of the zero-sequence current; a zero-sequence voltage discrimination circuit that detects a zero-sequence voltage based on the voltage value signal from the voltage value signal processing circuit and outputs a phase signal of the zero-sequence voltage; and a phase signal and zero-sequence voltage from the zero-sequence current discrimination circuit. A phase determination circuit that compares the phase with the phase signal from the determination circuit and outputs a determination signal indicating whether the ground fault fault point is on the power supply side or the load side based on the phase comparison; a no-voltage detection circuit that detects a no-voltage state of the distribution line when the circuit breaker trips and outputs a no-voltage detection signal; a short-circuit detection signal output from the short-circuit detection circuit; a first AND circuit that inputs the no-voltage detection signal as a signal corresponding to a logical value of 1 and outputs a short-circuit display drive current, one of the determination signals output from the phase determination circuit, and the no-voltage a second AND circuit which inputs the no-voltage detection signal from the detection circuit as a signal corresponding to a logic value of 1 and outputs a directional display drive current; and a short circuit display drive current from the first AND circuit. It is characterized by comprising a short circuit indicator that displays a short circuit in response, and a ground fault direction indicator that displays a directional ground fault in response to the directional display drive current from the second AND circuit. Fault current detection and display device.