JPH065254B2 - Fault current detection display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a fault current detection and display device for detecting a short-circuit current or a ground fault current flowing in a distribution line and displaying a fault in the distribution line. is there.

(Prior art) Conventionally, when a ground fault occurs in a distribution line, first open the substation circuit breaker and then substation cutoff from the viewpoints of early detection of an accident section, separation of the failure section and early transmission of a sound section. The substation breakers are re-closed when they reach the ground fault section, as they are closed again and are sequentially turned on from the power source side section switch to re-transmit power to the healthy section. Then, when the circuit breaker of the substation is closed again, the division switch that divides the ground fault section is locked in the 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,
There is a drawback that it takes time to detect the ground fault point.

Therefore, the applicant has decided to solve
No. 9-281323 proposes a short-circuit / ground fault direction detection display device. This short-circuit / ground fault direction detection display device uses a rechargeable battery in a power supply circuit that supplies a drive current to its control circuit.

However, if the battery deteriorates and cannot supply a drive current of a predetermined voltage to the control circuit, the control circuit may not operate even if a fault current due to a short-circuit ground fault flows through the distribution line.

Configuration of the Invention (Means for Solving the Problems) The present invention has been made to solve the above problems, and the fault current detection display device of the present invention includes a control circuit for a control circuit at the time of interruption. A voltage normality display drive circuit for connecting a backup drive power supply for supplying the drive current to drive the power supply voltage check indicator to a normal display when the voltage of the backup drive power supply is held at a predetermined voltage; The gist of the invention is to provide a voltage drop display drive circuit for driving the power supply voltage check display device to a low voltage display when the voltage of the backup drive power supply drops below a predetermined voltage.

(Operation) With the above configuration, the voltage normality display circuit drives the power supply voltage check indicator to a normal display when the voltage of the backup drive power supply is held at the predetermined voltage.

On the contrary, when the voltage of the backup drive power supply drops below a predetermined voltage, the voltage drop display drive circuit drives the power supply voltage check indicator to the low voltage display.

(Embodiment) An embodiment in which the present invention is embodied in a short-circuit ground fault direction detection display device will be described below with reference to FIGS. 1 to 6.

(Detector) In FIG. 1, first, the detector of the short-circuit ground fault direction detection display device 1 will be described. The detector is a first current detector that is attached and arranged to the distribution line L of each phase. Second and third current transformers CT1, CT2, CT3 and distribution line L
A zero-phase current transformer (hereinafter referred to as ZCT) 2 and a zero-phase voltage detector (hereinafter referred to as ZPD) 3 are provided as a zero-phase current detector that detects a zero-phase current flowing in the.

The first, second, and third current transformers CT1, CT2, C
T3 outputs a transformation current from its secondary side when a short-circuit current flows through the distribution line.

P9 and P10 are output terminals of ZCT2, and P11 and P10.
Reference numeral 12 is an output terminal of ZPD3.

(Control circuit) The control circuit is roughly divided into a short-circuit detection unit, a no-voltage detection unit, a short-circuit determination unit, a short-circuit indicator drive unit, a phase comparison determination circuit, a ground fault direction indicator drive unit, a power supply unit, and a time limit unit. It is configured.

Hereinafter, each unit will be described in detail with reference to the drawings.

I. Short Circuit Detection Section The short circuit detection section is composed of the first, second and third short circuit detection circuits Xa,
It is composed of Zb and Xc.

First, the first short circuit detection unit Xa will be described.

A full-wave rectifier 6 as a rectifier circuit is connected between both terminals connected to the first current transformer CT1 via choke coils 5a and 5b. A surge absorber 7 as a surge absorbing circuit is connected between both terminals.

A parallel circuit of a smoothing capacitor C1 and a resistor R1 is connected between the plus and minus terminals of the full wave rectifier 6.
Similarly, between the positive and negative terminals of the full-wave rectifier 6, there is a resistor R2, a changeover switch S, and a resistor R having different resistance values.
A series circuit including a parallel circuit of 3 and the resistor R4 and a light emitting diode LED of the photocoupler PC is connected. By switching and connecting the change-over switch S to the side of the resistor R3 or the resistor R4, the short-circuit ground fault direction detection display device 1 can be attached to the distribution line L through which different steady load currents flow. ing.

Between the output terminal P13 (plus terminal) of the power supply circuit Z and the minus terminal of the full-wave rectifier 6 described later, a series circuit of the emitter / collector of the switching transistor Tr1 and the resistor R5 connected through the collector is connected. ing. A diode D1 is connected to the collector of the switching transistor Tr1. The full-wave rectifier 6
Resistor R6, the emitter / collector of the phototransistor PTr of the photocoupler PC is connected between the negative terminal of the resistor R6 and the base terminal of the switching transistor Tr1, and the positive terminal of the resistor R6 and the output terminal P1.
A resistor R7 is connected between the resistor R3 and the resistor R3.

Therefore, when the short-circuit current flows through the distribution line L, the first current transformer CT1 outputs the transformed current based on the short-circuit current, and the full-wave rectifier 6 full-wave rectifies the transformed current. The photocoupler PC receives the full-wave rectified analog signal and digitally outputs it by the light emitting diode LED and the phototransistor PTr. Further, when the level of the digital signal applied to the base terminal is a predetermined value, the switching transistor Tr1 is turned on and outputs a short circuit current detection signal.

The resistors R1 to R7, the photocoupler PC, the switching transistor Tr1 and the diode D1 constitute a current discrimination switching circuit 50 in FIG.

The surge absorbing circuit 7, the rectifying circuit 6, and the current discriminating switching circuit 50 together form a first short circuit detecting circuit X.
a is configured.

The second short-circuit detection circuit Xb and the third short-circuit detection circuit Xc are configured in the same manner as the first short-circuit detection unit, and therefore, the same reference numerals are given to the same configurations and the description thereof is omitted. In addition,
A resistor R14 is connected between the resistor R1 and the negative terminal of the full-wave rectifier 6 in the third short circuit detection circuit Xc.

II. Non-voltage detection unit Next, the non-voltage detection unit will be described.

In the third short-circuit detection circuit Xc, a diode array Da is connected between the negative terminal of the resistor R1 and the negative terminal of the full-wave rectifier 6, and the plus terminal side of the diodes in the middle of the diode array Da1 and the full-wave rectifier. Between the negative terminal of 6 is connected a series circuit of resistors R15 and R16 and a parallel circuit of a noise-preventing capacitor C2.

In addition, the output terminal P13 of the power supply circuit and the full-wave rectifier 6 described later.
A resistor R17 and a transistor Tr2 are placed between the negative terminals of
Is connected to the collector and emitter thereof, and the positive terminal of the resistor R16 is connected to the base terminal of the transistor Tr2. Further, a capacitor C3 is connected between both terminals of the resistor R16.

The collector of the transistor Tr2 has an inverter In1.
Input terminal is connected, and the knot circuit 13 is connected to the output terminal of the inverter In1.

Then, when the distribution line L is in a steady state, the voltage between the diode arrays is divided by the resistors R15 and R16, and the transistor Tr2 becomes conductive when the voltage of the resistor R16 is applied to the base terminal, so that the voltage between the diode arrays is increased. The signal is voltage-amplified and applied to the input terminal of the inverter In1.

Therefore, since the collector-emitter voltage of the transistor Tr2 becomes 0, the signal corresponding to the logical value 0 is applied to the input terminal of the inverter In1, and the signal corresponding to the logical value 1 is output from the output terminal thereof. It Then, the knot circuit 13 outputs the signal corresponding to the logical value 0 based on the signal corresponding to the logical value 1.

On the contrary, when the circuit breaker of the substation trips due to a short-circuit accident in the distribution line L, the voltage between the diode arrays becomes no voltage, so that the base terminal of the transistor Tr2 has the voltage of the resistor R16 (that is, no voltage). Is applied, the transistor Tr2 is turned off. Then, since the transistor Tr2 is off, the voltage between the collector and the emitter of the transistor Tr2, that is, the signal corresponding to the logical value 1 is applied to the inverter In1. Therefore, the signal corresponding to the logical value 0 is output from the output terminal of the inverter In1, and the knot circuit 13 rectangularizes the waveform based on the signal corresponding to the logical value 0.
A signal (no-voltage detection signal) corresponding to the logical value 1 is output.

The diode array Da, the resistors R15 to R17, the capacitors C2 and C3, and the transistor Tr2 constitute a no-voltage detection circuit 51.

Further, the inverter In1 and the knot circuit 13 constitute a second waveform manipulating circuit 52.
The non-voltage detector is composed of.

III, short circuit determination unit Next, the first to third short circuit detection circuits Xa, Xb. A short circuit determination unit for inputting a short circuit detection signal, which is a digital signal output from xc, and a non-voltage detection signal from the non-voltage detection circuit 51 via the second waveform manipulation circuit 52 will be described.

The negative terminals of the diode D1 in each of the short circuit detection circuits Xa, Xb, and Xc are connected to each other, and the negative terminal of the diode D1 is connected to the first through the AND circuit 8 as the first waveform operation circuit and the resistor R9. It is connected to one input terminal of an AND circuit 9 as a gate circuit. A parallel circuit of a resistor R8 and a capacitor C4 is connected between the negative terminal of the diode D1 and the negative terminal of the full-wave rectifier 6, and the input terminal of the AND circuit 8 corresponds to a logical value of 1 for a predetermined time depending on the time constant of the CR circuit. Resistance R
A voltage of 8 is applied.

A signal memory circuit 53 is formed by the resistor R8 and the capacitor C4.

A switching transistor T is provided between the output terminal P13 (plus terminal) of the power supply circuit Z and the minus terminal of the full-wave rectifier 6.
A series circuit of a collector / emitter of r3 and a resistor R10 connected via the emitter is connected, and a capacitor C5 is connected in parallel between both terminals of the resistor R10.
The emitter terminal of the switching transistor Tr3 is connected to the gate terminal of the thyristor SCR1 described later, and the voltage of the resistor R10 is applied.

The output terminal of the AND circuit 9 is connected to the base terminal of the switching transistor Tr3 via the resistor R11. A resistor R12 is connected between the negative terminal of the resistor R11 and the negative terminal of the full-wave rectifier 6, and the voltage of the resistor R12 is applied to the base terminal of the switching transistor Tr3.

Therefore, when a signal corresponding to the logical value 1 is input to the AND circuit 8 for a predetermined time, the AND circuit 8 corresponds to the logical value 1 and outputs a signal corresponding to the logical value 1 which is a rectangular wave (short circuit current detection signal). ) Is output to the AND circuit 9. Same AND circuit 9
When the signal corresponding to the logic value 1 (non-voltage detection signal) from the non-voltage detection circuit 51 is applied while the signal corresponding to the logic value 1 from the AND circuit 8 is applied, Based on this, the first switch signal corresponding to the logical value 1 is output. Then, the voltage of the resistor R12 is applied to the base terminal of the switching transistor Tr3 based on the first switch signal, so that the switching transistor Tr3 is turned on (conducted).

The signal memory circuit 53, the AND circuit (first waveform operation circuit) 8, and the AND circuit (first gate circuit) 9 constitute a short circuit determination section.

IV. Drive Unit of Short-Circuit Indicator Next, the drive unit of the short-circuit indicator Ha will be described.

A series circuit of a diode D2, a charging resistor R13, and a capacitor C6 as a driving power supply is connected between the output terminal P13 (plus terminal) of the power supply circuit Z described later and the negative terminal of the full-wave rectifier 6 in the first short-circuit detection circuit Xa. Therefore, the capacitor C6 is always charged. Between the positive terminal of the capacitor C6 and the negative terminal of the full-wave rectifier 6 of the first detection circuit Xa, a series circuit of the anode / cathode of the thyristor SCR1, the diode D3, and the set terminal 10 / common terminal 11 of the short-circuit indicator Ha. Are connected. A drive flywheel diode D4 is connected between the set terminal 10 and the common terminal 11 of the short-circuit indicator Ha.

Therefore, when the switching transistor Tr3 is turned on (conducted), a voltage is applied to the capacitor C5 and the resistor R10. As a result, the capacitor C5 and the resistor R10
Therefore, a voltage is applied to the gate terminal of the thyristor SCR1 to make the thyristor SCR1 conductive. When the thyristor SCR1 is turned on, the electric charge of the capacitor C6 is discharged, and the short-circuit display drive current is output to the short-circuit indicator Ha.

The diode D2, the charging resistor R13 and the capacitor C
6 together with the display drive power supply charging circuit 54, the resistor R10, the capacitor C5 and the thyristor S.
A first switching circuit 55 (see FIG. 2) is configured by CR1.

A resistor R18 and a switching transistor T are provided between the output terminal P13 (plus terminal) of the power supply circuit Z described later and the minus terminal of the full-wave rectifier 6 in the first short-circuit detection circuit Xa.
A series circuit of collector and emitter of r4 is connected. A series circuit of a diode D5 and a resistor R19 is connected between the base terminal of the switching transistor Tr4 and the cathode terminal of the thyristor SCR1. Further, the negative terminal of the resistor R19 and the full-wave rectifier 6
A resistor R20 is connected between the negative terminals of the resistor R20 and the voltage of the resistor R20 is applied to the base terminal of the switching transistor Tr4.

A series circuit of the emitter / collector of the switching transistor Tr5 and the resistor R21 is connected between the output terminal P13 (plus terminal) of the power supply circuit Z described later and the minus terminal of the full-wave rectifier 6 in the first short-circuit detection circuit Xa. . Further, a capacitor C7 is connected between both terminals of the resistor R21, and a positive terminal of the capacitor C7 is connected to a clear terminal 22 of an IC14 of a time limit circuit T described later via a diode D13.

A resistor R22 is connected between the base terminal of the switching transistor Tr5 and the collector terminal of the switching transistor Tr4, and a collector-emitter voltage of the switching transistor Tr4 is applied to the base terminal of the switching transistor Tr5. There is.

Therefore, when the thyristor SCR1 is not conducting, the switching transistor Tr4 and the switching transistor Tr5 are off. When the thyristor SCR1 is turned on, the voltage of the resistor R20 is applied to the base terminal of the switching transistor Tr4, so that the switching transistor Tr4 is turned on (conducted). Then, the switching transistor Tr
The potential of the base terminal of the transistor 5 is lowered, and the switching transistor Tr5 is turned on. Then, the capacitor C9
According to the time constant of the CR circuit, the clear control signal SG1 is transmitted from the resistor R21 and the resistor R21 to the clear terminal 2 of the IC14 of the time circuit T.
2 is output.

The voltage amplifying circuit 5 includes the diode D5, the resistors R18 to R22, and the switching transistors Tr4 and Tr5.
6 are configured.

Between the positive terminal of the capacitor C6 and the reset terminal 12 of the short-circuit indicator Ha, the anode of the thyristor SCR2
A series circuit of the cathode and the diode D6 is connected. A flyback diode D7 for recovery driving is connected between the reset terminal 12 and the common terminal 11 of the short-circuit indicator Ha. The gate terminal of the thyristor SCR2 has a Schmitt trigger circuit SC of a time circuit T described later.
Are connected via a resistor R23 and a diode D8. Further, a parallel circuit of a resistor R24 and a capacitor C8 is connected between the gate terminal of the thyristor SCR2 and the negative terminal of the full-wave rectifier 6.

Therefore, when the display return signal Sig4 is output from the Schmitt trigger circuit SC, the capacitor C8 and the resistor R
A voltage is applied to 24. As a result, a voltage is applied to the gate terminal of the thyristor SCR2 from the capacitor C8 and the resistor R24, and the thyristor SCR2 is made conductive. Then, due to the conduction of the thyristor SCR2, the charge of the capacitor C6 is discharged, and the short-circuit indicator Ha
The recovery drive current is output to.

The resistor R24, capacitor C8, thyristor SCR2
The short-circuit indicator recovery switching circuit 57 (second
(See the figure) is configured.

V. Short Circuit Indicator Here, the short circuit indicator Ha will be described in detail with reference to FIGS. 4 to 6.

The short-circuit indicator Ha is composed of a plurality of magnetic reversal indicators. In one magnetic reversal display, a disk 15 whose both ends are magnetized to have N poles and S poles is rotatably supported around a rotary shaft 16, and a round bar-shaped stator 17 is a disk 15.
The magnetic pole portion 17a corresponding to the S pole and the magnetic pole portion 17b corresponding to the N pole of the disk 15 are formed. The stator 17 is preferably made of a material having a small coercive force. Both ends of the common terminal 11 and the set terminal 10 are connected between the magnetic pole portions 17a and 17b so that the magnetic pole portions 17a and 17b are magnetized to have the same polarity with respect to the magnetic poles at both ends of the disk 15 in the state shown in FIG. The drive coil 18 is wound.

In addition, the magnetic pole portions 17 are adjacent to the drive coil 18.
A return drive coil 19 connected between the common terminal 11 and the reset terminal 12 so that the magnetic pole portions 17a and 17b are magnetized to have the same polarity between the magnetic poles at both ends of the disk 15 in the state shown in FIG. Is wound.

Marks of different colors are provided on the front surface 15a and the back surface 15b of the disk 15 (in this embodiment, the front surface 15a is black,
The back surface 15b is displayed in red.

The drive coil 18 and the return drive coil 19 of each magnetic reversal display are connected in parallel with each other (see FIG. 6).

Therefore, when the short-circuit display drive current flows to the short-circuit indicator Ha through the ground terminal 10, each drive coil 18 is excited,
As shown in FIG. 5, the magnetic pole portion 17a is magnetized to the S pole and the magnetic pole portion b is magnetized to the N pole, and the N pole of each disk 15 is magnetic pole portion 1
7a (S pole) is turned so that the S pole faces the magnetic pole portion 17b (N pole), and the back surface 15 of each disk 15 is rotated.
The sign attached to b is displayed all at once to the outside (short-circuit display).

On the contrary, when the return drive current flows to the short-circuit indicator Ha through the reset terminal 12, each return drive coil 19 is excited, and the magnetic pole portion 17a becomes the N pole and the magnetic pole portion 17b becomes the magnetic pole portion 17b as shown in FIG. Each disk 15 is magnetized to the S pole, and the N pole of each disk 15 is the magnetic pole portion 17a (N pole) and the S pole thereof is the magnetic pole portion 17b.
Each disc 1 is rotated so as to face the (S pole) in reverse.
The markers attached to the surface 21a of No. 5 are constantly displayed all at once to the outside.

VI. Phase Comparison Discrimination Circuit Next, the phase comparison discrimination circuit 20 will be described.

The phase comparison / discrimination circuit 20 outputs the output terminal P9 of the ZCT2,
It is connected to P10 and the output terminal IVP1 of ZPD3
1, P12.

In FIG. 2, the in-phase comparison / determination circuit 11 outputs a zero-phase current detection signal output via the surge absorption circuit 58 when ZCT2 detects a zero-phase current, and a surge absorption circuit 59 when ZPD3 detects a zero-phase voltage. When a zero-phase voltage detection signal output via is input, the phase comparison circuit 60 compares the phases of the zero-phase current and the zero-phase voltage based on both signals.

If the phase comparison circuit 61 compares the phase of the zero-phase voltage with the phase of the zero-phase voltage as a reference and the phase of the zero-phase current approaches 0 to 110 degrees, the ground fault point is on the right side of the display. Then, the control signal is output. On the contrary, the phase discriminating circuit 61 outputs a control signal assuming that the ground fault point is on the left side of the display when the phase of the zero phase current is 180 degrees out of phase as a result of the phase comparison of the phase comparing circuit 60. ing.

Further, the switching circuit 62 is adapted to be turned on based on the control signal of the phase discrimination circuit 61. Further, the signal memory circuit 63 responds to the ON operation of the switching circuit 62, and when the phase of the zero-phase current is close to 0 to 110 degrees ahead, it outputs the determination signal corresponding to the logical value 1 from the right side display output terminal P14 for a certain time. It is designed to output.
Further, the signal memory circuit 63 responds to the ON operation of the switching circuit 62, and 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 left side of the display and the logical value from the left display output terminal P15. The determination signal corresponding to 1 is output for a certain period of time.

The surge absorption circuits 58 and 59, the phase comparison circuit 60, the phase determination circuit 61, the switching circuit 62, and the signal memory circuit 63 constitute a phase comparison determination circuit 20.

VII. Drive Unit of Ground Fault Direction Indicator The input terminal of the AND circuit 21 as the second gate circuit is connected to the right side display output terminal P14, and when the judgment signal corresponding to the logical value 1 is input from the right side display output terminal P14. The second switch signal corresponding to the logical value 1 is applied from its output terminal.

A series circuit of a diode D9, a charging resistor R25, and a capacitor C9 as a driving power source is connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 so that the capacitor C9 is constantly charged.

The diode D9, the charging resistor R25, the capacitor C9
The display driving power supply charging circuit 64 in FIG.

A thyristor S is provided between the positive terminal of the capacitor C9 and the set terminal 10 of the right direction indicator Hb1 for displaying the right side.
A series circuit of CR3 and diode D10 is connected, and the negative terminal of the capacitor 9 is connected to the common terminal 11 of the right direction indicator Hb1. Also, the right direction indicator Hb1
A drive flywheel diode D11 is connected between the set terminal 10 and the common terminal 11.

A resistor R2 connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 via the collector and the emitter of the switching transistor Tr6.
A series circuit with 6 is connected. A capacitor C10 is connected in parallel to both terminals of the resistor R26. The emitter terminal of the switching transistor Tr6 is connected to the gate terminal of the thyristor SCR2, and the base terminal of the switching transistor Tr6 is the output terminal of the AND circuit 21 and the resistor R2.
It is connected via 7. Further, a resistor R28 is connected between the negative terminal of the resistor R27 and the ground terminal P16, and a voltage is applied to the base terminal of the switching transistor Tr6.

Therefore, when the second switch signal corresponding to the logical value 1 is output from the AND circuit 21, the voltage of the resistor R28 is applied to the base terminal of the switching transistor Tr6. As a result, the switching transistor Tr6 is turned on (conducted), and the capacitor 10 and the resistor R26 are turned on.
A voltage is applied to. As a result, a voltage is applied to the gate terminal of the thyristor SCR3 from the capacitor C10 and the resistor R26, and the thyristor SCR3 is made conductive. When the thyristor SCR3 is turned on, the capacitor C9
Is discharged, and a ground fault display drive current as a ground fault direction display signal is output to the right direction indicator Hb1.

The resistors R26 to R28 and the switching transistor T
The second switching circuit 65 in FIG. 2 is configured by r6, the capacitor C10, and the thyristor SCR3.

A resistor R29 and a switching transistor T are provided between the output terminal P13 and the ground terminal P16 of the power supply circuit Z described later.
A series circuit of collector and emitter of r7 is connected. A series circuit of a diode D12 and a resistor R30 is connected between the base terminal of the switching transistor Tr7 and the cathode terminal of the thyristor SCR3. Further, the negative terminal of the resistor R30 and the ground terminal P1
A resistor R31 is connected between 6 and the voltage of the resistor R31 is applied to the base terminal of the switching transistor Tr7.

A series circuit of an emitter / collector of a switching transistor Tr8 and a resistor R32 is connected between an output terminal P13 of a power supply circuit Z and a ground terminal, which will be described later. further,
A capacitor C11 is connected between both terminals of the resistor 32, and a positive terminal of the capacitor C11 has a diode D14 connected to a clear terminal 22 of an IC14 of a time circuit T described later.
Connected through.

A resistor R33 is connected between the base terminal of the switching transistor Tr8 and the collector terminal of the switching transistor Tr7 so that the collector-emitter voltage of the switching transistor Tr7 is applied to the base terminal of the switching transistor Tr8. There is.

Therefore, when the thyristor SCR3 is not conducting, the switching transistors Tr7 and Tr8 are off. When the thyristor SCR3 becomes conductive, the voltage of the resistor R31 is applied to the base terminal of the switching transistor Tr7, so that the switching transistor Tr7 is turned on (conductive).

Then, the potential of the base terminal of the switching transistor Tr8 drops, and the switching transistor Tr8 turns on. Then, the capacitor C11 and the resistor R32
And the clear control signal SG depending on the time constant of the CR circuit.
2 outputs to the clear terminal 22 of the IC 14 of the time limit circuit T.

The diode D12, the resistors R29 to R33, and the switching transistors Tr7 and Tr8 form a voltage amplifier circuit 66.

A series circuit of a diode D20, a charging resistor R43, and a capacitor C15 as a recovery driving power source is connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 so that the capacitor C15 is constantly charged. .

The diode D20, the charging resistor R43, the capacitor C
The reset drive power supply charging circuit 67 in FIG. 2 is constituted by 15.

The positive terminal of the capacitor C15 and the right direction indicator H
The thyristor SCR5 is provided between the reset terminals 12 of b1.
A series circuit of the anode / cathode and the diode D21 is connected. Further, a return drive flywheel diode D22 is connected between the reset terminal 12 and the common terminal 11 of the right direction indicator Ha. The thyristor S
A Schmitt trigger circuit SC of a time-limited circuit T described later is connected to the gate terminal of CR5 via a resistor R23 and a diode D23. Furthermore, the thyristor SCR
A parallel circuit of a resistor R44 and a capacitor C16 is connected between the gate terminal of No. 5 and the ground terminal P16.

Therefore, when the display return signal Sig4 is output from the Schmitt trigger circuit SC, a voltage is applied to the capacitor C16 and the resistor R44. As a result, the capacitor C16
A voltage is applied from the resistor R44 to the gate terminal of the thyristor SCR5 to make the thyristor SCR5 conductive. Then, due to the conduction of the thyristor SCR5, the electric charge of the capacitor C15 is discharged, and the return drive current is output to the right direction indicator Hb1.

The resistor R44, capacitor C16, thyristor SCR
5 and 5 constitute a switching circuit 68 for returning to the ground fault direction indicator in FIG.

Further, the positive terminal of the capacitor C11 is connected to the gate terminal of the thyristor SCR6 for return driving for the leftward direction indicator Hb2 described later through a diode D24. A gate trigger voltage is applied to turn on the thyristor SCR6 when the switching transistor Tr8 turns on.

Similarly, an input terminal of an AND circuit 23 as a second gate circuit is connected to the left side display output terminal P15. That is, when the AND circuit 23 inputs the determination signal corresponding to the logical value 1 from the left display output terminal P15,
The second switch signal corresponding to the logical value 1 is applied from the output terminal.

A series circuit of a diode D15, a charging resistor R34, and a capacitor C12 as a driving power supply is connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 so that the capacitor C12 is constantly charged.

The diode D15, charging resistor R34, capacitor C
2, the display drive power source charging circuit 69 in FIG.
Is configured.

A series circuit of a thyristor SCR4 and a diode D16 is connected between the positive terminal of the capacitor C12 and a set terminal 10 of a leftward direction indicator Hb2 for performing leftward display, and the negative terminal of the capacitor C12 is a leftward direction indicator Hb2.
Is connected to the common terminal 11. Further, a driving flywheel diode D17 is connected between the set terminal 10 and the common terminal 11 of the left direction indicator Hb2.

A resistor R3 connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 via the collector and the emitter of the switching transistor Tr9.
A series circuit with 5 is connected. A capacitor C13 is connected in parallel to both terminals of the resistor R35. The emitter terminal of the switching transistor Tr9 is connected to the gate terminal of the thyristor SCR4, and the base terminal of the switching transistor Tr9 is the output terminal of the AND circuit 23 and the resistor R3.
It is connected via 6. Further, a resistor R37 is connected between the negative terminal of the resistor R36 and the ground terminal P16, and a voltage is applied to the base terminal of the switching transistor Tr9.

Therefore, when the second switch signal corresponding to the logical value 1 is output from the AND circuit 23, the voltage of the resistor R37 is applied to the base terminal of the switching transistor Tr9 based on the second switch signal. As a result, the switching transistor Tr9 is turned on (conducted),
A voltage is applied to the capacitor C13 and the resistor R35. As a result, a voltage is applied to the gate terminal of the thyristor SCR4 from the capacitor C13 and the resistor R35, and the thyristor SCR4 is made conductive. And thyristor S
Due to conduction of CR4, the electric charge of the capacitor C12 is discharged, and a ground fault display drive current as a ground fault direction display signal is output to the left direction indicator Hb2.

The resistors R35 to R37 and the switching transistor T
The r9, the capacitor C13, and the thyristor SCR4 form a second switching circuit 70 in FIG.

A resistor R38 and a collector-emitter series circuit of the switching transistor Tr10 are connected between the output terminal P13 (plus terminal) of the power supply circuit Z and a ground terminal P16, which will be described later. Same switching transistor Tr
A series circuit of a diode D18 and a resistor R39 is connected between the base terminal of 10 and the cathode terminal of the thyristor SCR4. Further, a resistor R40 is connected between the negative terminal of the resistor R39 and the ground terminal P16, and the resistor R40 is connected to the base terminal of the switching transistor Tr10.
A voltage of 40 is applied.

A switching transistor Tr is provided between the output terminal P13 (plus terminal) and the ground terminal P16 of the power supply circuit Z described later.
A series circuit of 11 emitters and collectors and a resistor R41 is connected. Further, a capacitor C14 is connected between both terminals of the resistor R41, and a positive terminal of the capacitor C14 is connected to a clear terminal 22 of an IC14 of a time-limit circuit T described later via a diode D19.

A resistor R42 is connected between the base terminal of the switching transistor Tr11 and the collector terminal of the switching transistor Tr10, and a collector-emitter voltage of the switching transistor Tr10 is applied to the base terminal of the switching transistor Tr11. There is.

Therefore, when the thyristor SCR4 is not conducting, the switching transistor Tr10 and the switching transistor Tr11 are off. When the thyristor SCR4 is turned on, the voltage of the resistor R40 is applied to the base terminal of the switching transistor Tr10, so that the switching transistor Tr10 is turned on.

Then, the potential of the base terminal of the switching transistor Tr11 drops, and the switching transistor Tr1
1 turns on. Then, the capacitor C14 and the resistor R
41 and a clear control signal SG3 is output to the clear terminal 22 of the IC 14 of the time limit circuit T according to the time constant of the CR circuit.

The diode D18, the resistors R38 to R41, and the switching transistors Tr10 and Tr11 form a voltage amplifier circuit 71.

A series circuit of a diode D25, a charging resistor R45, and a capacitor C17 as a recovery driving power supply is connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the ground terminal P16 so that the capacitor C17 is constantly charged. .

The diode D25, the charging resistor R45, the capacitor C
17, the recovery drive power supply charging circuit 72 in FIG.
Is configured.

The positive terminal of the capacitor C17 and the left direction indicator H
The thyristor SCR6 is provided between the reset terminals 12 of b2.
A series circuit of the anode / cathode and the diode D26 is connected. Further, a return drive flywheel diode D27 is connected between the reset terminal 12 and the common terminal 11 of the left direction indicator Hb2. At the gate terminal of the thyristor SCR6, a Schmitt trigger circuit SC of a time circuit T described later is provided with a resistor R23 and a diode D28.
Connected through. Furthermore, the thyristor SC
A resistor R46 is placed between the gate terminal of R6 and the ground terminal P16.
And a parallel circuit of a capacitor C18 are connected.

Therefore, when the display return signal Sig4 is output from the Schmitt trigger circuit SC, a voltage is applied to the capacitor C18 and the resistor R46. As a result, the capacitor C18
A voltage is applied to the gate terminal of the thyristor SCR6 from the resistor R46 to make the thyristor SCR6 conductive. Then, due to the conduction of the thyristor SCR6, the electric charge of the capacitor C17 is discharged, and the return drive current is output to the left direction indicator Hb2.

The resistor R46, capacitor C18, thyristor SCR
6 and 6 form the ground fault direction indicator return switching circuit 73 in FIG.

Further, the plus terminal of the capacitor C14 is connected to the gate terminal of the thyristor SCR5 for the right direction indicator Hb1 described later through the diode D29. And
A gate trigger voltage is applied to turn on the thyristor SCR5 when the switching transistor Tr11 is turned on.

VIII. Ground fault direction indicator A pair of right side direction indicators Hb constituting the ground fault direction indicator
1, the left direction indicator Hb2 has the same configuration as the short-circuit indicator Ha, and when a ground fault display drive current flows through both the indicators Hb1 and Hb2 via the set terminal 10, each drive coil (not shown). ) Is excited, the markers attached to the back surface of each disk are simultaneously displayed to the outside (ground fault direction display).

On the contrary, the reset terminal 12 is attached to both the indicators Hb1 and Hb2.
When a return drive current flows through the return drive coils, the return drive coils (not shown) are excited, so that the markers attached to the surface of each disk are constantly displayed all at once outside.

IX. Time Limit Unit Next, the time limit circuit T will be described.

The IC 14 has a resistor R50, a capacitor C20, and a resistor R5.
An oscillator circuit 74 consisting of 1 is connected to form an IC timer, and the IC 14 divides the number of oscillations of the oscillator circuit 74.

The output terminal P13 (plus terminal) of the power supply circuit Z and the IC
A switching transistor T is provided between the negative terminals of 14
A series circuit of a collector / emitter of r12 and a resistor R52 connected via the emitter is connected. A capacitor C21 connected to both terminals of the resistor R52
Is for noise prevention.

The output terminal of the IC 14 is connected to the base terminal of the switching transistor Tr12 via a resistor R53,
A resistor R54 is connected between the base terminal of the switching transistor Tr12 and the negative terminal of the full-wave rectifier 6 in the third short circuit detection circuit Xc so that the voltage of the resistor R54 is applied to the base terminal of the switching transistor Tr12. It has become.

Further, a series circuit of the collector and emitter of the switching transistor Tr13 of the resistor R55 is connected between the output terminal P13 (plus terminal) of the power supply circuit Z and the minus terminal of the IC14. A capacitor C22 is connected between the positive terminal of the resistor R52 and the base terminal of the switching transistor Tr13, and a resistor is provided between the base terminal of the switching transistor Tr13 and the negative terminal of the full-wave rectifier 6 in the third short circuit detection circuit Xc. R
56 is connected. Then, the capacitor C22
And the resistor R56 form a differentiating circuit.

The negative terminals of the diodes D13, D19 and D14 and the full-wave rectifier 6 in the third short circuit detection circuit Xc.
A resistor R57 is connected between the negative terminals of the.

The display restoration signal generating circuit 75 in FIG. 2 is configured by the switching transistors Tr12 and Tr13, the capacitor C21, the resistor R23, the resistors R53 to R56, and the Schmitt trigger circuit SC.

When the IC 14 inputs the clear control signals Sig1, Sig2, Sig3 from the above circuits, the IC timer clears the division of the oscillation number of the oscillation circuit 74 and starts the division of the oscillation number again. Then, when the IC 14 is divided into a predetermined number of times, that is, when a predetermined time has elapsed, the IC 14 applies a time-up signal for a predetermined time from its output terminal via the resistor R53. Then, the voltage of the resistor R54 is applied to the base terminal of the switching transistor Tr12, so that the switching transistor Tr12 is turned on (conducted) while the time-up signal is applied,
A voltage is applied to the differentiation circuit of the capacitor 22 and the resistor R56.

As a result, a voltage is applied from the differentiating circuit to the gate terminal of the switching transistor Tr13 at the rise of the time-up signal for a predetermined time, so that the switching transistor Tr13 is turned on (conducted) for the time constant time of the capacitor C22 and the resistor R56. It is supposed to be done. Then, based on the on / off operation of the switching transistor Tr13, the Schmitt trigger circuit SC waveform-shapes the signal applied to the Schmitt trigger circuit SC, and outputs the display return signal Sig4 to each of the indicators Ha, Hb1, Hb2. It is designed to output.

X. Power Supply Unit Next, the power supply unit will be described.
And a power supply voltage check circuit 78.

The power supply circuit Z is provided in the full-wave rectifier 6 in the third short circuit detection circuit Xc. That is, the series circuit of the transistor Tr14, the diode D30, and the rechargeable battery B is connected between both terminals of the diode array Da. A resistor R58 is connected between the collector terminal and the base terminal of the transistor Tr14, and a Zener diode ZD is connected between the base terminal of the transistor Tr14 and the negative terminal of the full-wave rectifier 6.

The diode array Da constitutes the first constant voltage circuit 76 in FIG. 2, and the resistor R58, the transistor Tr14 and the Zener diode ZD constitute a second constant voltage circuit 77.

The power supply circuit Z is configured to charge the battery B by making the forward voltage across the diode array Da2 further constant by the transistor Tr14 and the Zener diode ZD.

Then, when a steady load current is flowing in the distribution line L, the backup battery B is not consumed, and the drive current is supplied to the respective parts by the load current. When the circuit breaker at the substation trips and the load current no longer flows through the distribution line L, the backup battery B supplies the drive current required for each part from the output terminal P13.

The power supply voltage check circuit 78 will be described.

A resistor R59 and a collector / emitter series circuit of a transistor Tr15 are connected between both terminals of the battery B, and a series circuit of a resistor R60 and a resistor R61 is connected. A capacitor C23 is connected to both terminals of the resistor R61, and a positive terminal of the resistor R61 is connected to a base terminal of the transistor TR15.
The voltage of the resistor R61 is applied to the base terminal of the transistor Tr15.

Between the terminals of the battery B, a diode D31, a resistor R62, a common terminal 28 of the power supply voltage check indicator Hc,
The set terminal 29, the diode D32, and the collector / emitter of the switching transistor Tr16 are connected. Also, the set terminal 2 of the power supply voltage check display Hc
A freewheel diode D33 is connected between 9 and the common terminal.

A series circuit of an inverter In2, a knot circuit 25, a capacitor C24, a resistor R63, an AND circuit 26 and a resistor R64 is connected between the collector terminal of the transistor Tr15 and the base terminal of the switching transistor Tr16. A resistor R65 is connected between the positive terminal of the resistor R63 and the negative terminal of the battery B, and a resistor R66 is connected between the base terminal of the switching transistor Tr16 and the negative terminal of the battery B.

Therefore, when the battery B holds the predetermined voltage, the transistor Tr15 is in the ON state with the partial voltage of the resistor R61 applied to the base terminal. Then, in this state, the signal corresponding to the logical value 0 is input to the inverter In2. Then, the inverter In2 applies the signal corresponding to the logical value 1 to the knot circuit 25, and the knot circuit 25 applies the signal corresponding to the logical value 0 based on the signal corresponding to the logical value 1 to the capacitor C24 and the resistor R6.
5, applied to R63. Since the AND circuit 26 inputs the signal corresponding to the logical value 0 from the CR circuit and applies the signal corresponding to the logical value 0 to the base terminal of the switching transistor Tr16 based on the signal, the switching transistor Tr16 is turned off. It becomes a state.

On the contrary, when the voltage of the battery B becomes equal to or lower than the predetermined voltage, the predetermined base voltage is not applied to the base terminal of the transistor 15, so that the transistor 15 is turned off. Then, the signal corresponding to the logical value 1 is input to the inverter In2, the inverter In2 outputs a signal corresponding to the logical value 0 to the knot circuit 25 based on the signal, and the knot circuit 25 changes the logical value to 0. A signal corresponding to the logical value 1 is applied to the capacitor C24 and the resistors R65 and R63 based on the corresponding signal. The AND circuit 26 is a logical value 1 from the CR differentiating circuit.
Input to the signal corresponding to, and the logical value 1 based on the signal
Since the signal corresponding to is applied to the base terminal of the switching transistor Tr16, the switching transistor Tr16 is turned on.

The switching transistors Tr15 and TR16, the inverter In2, the knot circuit 25, the AND circuit 26, the capacitor C24, the resistors R63 to R66, and the diode D.
The voltage drop display drive circuit 79 is constituted by 32.

A diode D34 and a collector / emitter of a switching transistor Tr17 are connected between the reset terminal 30 of the power supply voltage check indicator Hc and the negative terminal of the battery B.

A knot circuit 3 is provided between the output terminal of the inverter In2 and the base terminal of the switching transistor Tr17.
2, 33, a capacitor C25, a resistor R67, an AND circuit 34 and a resistor R68 are connected in series to connect the resistor R6.
A resistor R69 is connected between the positive terminal of 7 and the negative terminal of the battery B. A resistor R70 is connected between the base terminal of the switching transistor Tr17 and the negative terminal of the battery B. A freewheel diode D35 is connected between the reset terminal 30 and the common terminal of the power supply voltage check indicator Hc.

Therefore, when the knot circuit 32 receives the signal corresponding to the logical value 1 from the inverter In2, the knot circuit 32 receives the signal.
Outputs the signal corresponding to the logical value 0 to the knot circuit 33 based on the signal corresponding to the logical value 1, and the knot circuit 3
3 applies a signal corresponding to the logical value 1 to the capacitor C25 and the resistors R67 and R69 based on the signal. AND circuit 34 Since the signal corresponding to the logical value 1 from the CR differentiating circuit is input and the signal corresponding to the logical value 1 is applied to the base terminal of the switching transistor Tr17 based on the signal, the switching transistor Tr17 is turned on. It becomes a state.

On the contrary, when the inverter In2 outputs the signal corresponding to the logical value 0 to the knot circuit 32, the knot circuit 32 outputs the signal corresponding to the logical value 1 to the knot circuit 33 based on the signal corresponding to the logical value 0. The knot circuit 33 outputs a signal corresponding to a logical value of 0 to the capacitor C2 based on the signal.
5, applied to resistors R67 and R69. The AND circuit 34 inputs the signal corresponding to the logical value 0 from the CR circuit,
Since the signal corresponding to the logical value 0 is applied to the base terminal of the switching transistor Tr17 based on the signal, the switching transistor Tr17 is turned off.

The switching transistor Tr17 and the knot circuit 3
2, 33, AND circuit 34, capacitor C25, resistance R
The normal voltage display drive circuit 80 is composed of 67 to R69 and the diode D34.

XI. Power supply voltage check indicator The power supply voltage check indicator Hc is the short-circuit indicator Ha.
When the display drive current flows through the common terminal 28 and the set terminal 29, the drive coil (not shown) is excited, so that the mark attached to the back surface of the disk is externally arranged. Is displayed to indicate that the voltage of the battery B has dropped.

On the contrary, when the reset drive current flows through the common terminal 28 and the reset terminal 30, the power supply voltage check display H
The symbol c indicates that the return drive coil (not shown) is excited to display a mark attached to the surface of the disk to the outside, and the battery B holds a predetermined voltage value.

Operation of the Embodiment The operation of the control circuit of the short-circuit ground fault direction detection display device configured as described above will be described.

Now, when a steady load current is flowing in the distribution line L, in the power supply circuit Z, a small amount of the transformation current is output from the third current transformer CT3, and the transformation current is full-wave rectified by the full-wave rectifier 6. Then, the battery B of the power supply circuit Z is charged. Further, the power supply circuit Z serves as a driving power supply for the circuits Xa, Xb, and 20 and a capacitor C as a power supply for driving the display.
6, C9, C12, C15, C17 are charged.

Also, at this time, in the first and second short-circuit detection circuits Xa and Xb, the same small amount of transformation current is output from the first and second current transformers CT1 and CT2, and the transformation current is output to the full-wave rectifier 6. After the full-wave rectification, most of the resistance is R1
On the other hand, in the third short-circuit detection circuit Xc, it is consumed by the resistors R1, R15 and the diode array Da.

In this state, the circuit breaker of the substation does not have a tripping current, and the thyristors SCR1 to SCR6 of each circuit are off.

In this state, for example, when a short-circuit current that allows the circuit breaker of the substation to trip occurs in the distribution line L to which the first current transformer CT1 is attached, the first current transformer CT1 causes the first short-circuit detection circuit to trip. The transformation current is output to Xa. The transformed current is full-wave rectified by the full-wave rectifier 6, and the photocoupler PC inputs the full-wave rectified analog signal and digitally outputs the light-emitting diode LED and the phototransistor PTr. Then, the switching transistor Tr1 is turned on when the level of the digital signal applied to the base terminal is equal to or higher than a predetermined value. As a result, the voltage of the resistor R8 is applied as a signal corresponding to the logical value 1 to the AND circuit 8 for a predetermined time due to the time constant of the CR circuit of the resistor R8 and the capacitor C4.

Therefore, the AND circuit 8 corresponds to the logical value 1 and is a signal (short-circuit current detection signal) corresponding to the logical value 1 which is a rectangular wave.
Is output to the AND circuit 9.

On the other hand, when the circuit breaker of the substation trips due to the short-circuit current and, as a result, the distribution line L becomes non-voltage, the voltage between the diode arrays Da in the third short-circuit detection circuit Xc becomes non-voltage. The voltage (that is, no voltage) of the resistor R16 is applied to the base terminal of the transistor R2, and the transistor Tr2 is turned off. Then, since the transistor Tr2 is off, the inverter In
The voltage between the collector and the emitter of the transistor Tr2, that is, the signal corresponding to the logical value 1 is applied to 1.

Therefore, the signal corresponding to the logical value 0 is output from the output terminal of the inverter In1, and the knot circuit 13 rectangularizes the waveform based on the signal corresponding to the logical value 0 and outputs the logical value 1
The signal corresponding to (a non-voltage detection signal) is output.

The AND circuit 9 outputs the voltageless detection circuit 5 while the signal corresponding to the logical value 1 from the AND circuit 8 is being applied.
When the signal corresponding to the logical value 1 from 1 (no-voltage detection signal) is applied, the first switch signal corresponding to the logical value 1 is output based on both signals. Then, the voltage of the resistor R12 is applied to the base terminal of the switching transistor Tr3 based on the first switch signal, so that the switching transistor Tr3 is turned on (conducted).

Then, a voltage is applied to the capacitor C5 and the resistor R10. As a result, a voltage is applied to the gate terminal of the thyristor SCR1 from the capacitor C5 and the resistor R10 to make the thyristor SCR1 conductive. And thyristor S
Due to the conduction of CR1, the electric charge of the capacitor C6 is discharged, and the short-circuit display drive current is output to the short-circuit indicator Ha.

The short circuit indicator Ha displays a short circuit by this short circuit display drive current.

When the thyristor SCR1 becomes conductive, the resistance R20
Voltage of the switching transistor Tr4 is applied to the base terminal of the switching transistor Tr4.
Turns on (conducts). Then, the potential of the base terminal of the switching transistor Tr5 drops, and the switching transistor Tr5 turns on. Then, the clear control signal is output from the capacitor C9 and the resistor R21 to the clear terminal 22 of the IC 14 of the time limit circuit T according to the time constant of the CR circuit.

When the clear control signal is input, the IC 14 clears the division of the oscillation number of the oscillation circuit 74 and starts the division of the oscillation number again. Then, after a lapse of a predetermined time, the IC 14 applies a time-up signal for a predetermined time from its output terminal via the resistor R53. Then, the voltage of the resistor R54 is applied to the base terminal of the switching transistor Tr12, so that the switching transistor Tr12 is turned on (conducted) while the time-up signal is applied, and the differentiation circuit of the capacitor 22 and the resistor R56 is applied. A voltage is applied.

As a result, a voltage is applied from the differentiating circuit to the gate terminal of the switching transistor Tr13, so that the switching transistor Tr13 is connected to the capacitor C22,
The ON operation (conduction) is performed only for the differential value constant time of the resistor R56. Then, based on the on / off operation of the switching transistor Tr13, the Schmitt trigger circuit SC waveform-shapes the signal applied to the Schmitt trigger circuit SC, and outputs the display return signal Sig4 to the display Ha.

Display return signal Sig4 from Schmitt trigger circuit SC
Is output, a voltage is applied to the capacitor C8 and the resistor R24. As a result, the capacitor C8 and the resistor R24
Is applied to the gate terminal of the thyristor SCR2, and the thyristor SCR2 is made conductive. Then, due to the conduction of the thyristor SCR2, the charge of the capacitor C6 is discharged, and the return drive current is output to the short-circuit indicator Ha.

The return drive current resets the short-circuit indicator Ha and returns to the steady display state.

Also, when a short-circuit current capable of tripping the circuit breaker of the substation flows through the distribution line L to which the second and third current transformers CT2 and CT3 are attached, the short-circuit indicator Ha is similar to the above. A short-circuit is displayed, and after a certain period of time, the steady display state is restored.

Next, when a ground fault occurs in the distribution line L, the phase comparison / determination circuit 20 detects a zero-phase current and a zero-phase voltage flowing in the distribution line L via ZCT2 and ZPD3, and detects the zero-phase current and the zero-phase voltage. Perform voltage phase comparison.

Then, the phase comparison / discrimination circuit 20 determines that the ground fault point is on the right side when the phase of the zero-phase voltage is close to leading by 0 to 110 degrees with reference to the phase of the zero-phase voltage, and the logic from the right display output terminal P14. The determination signal corresponding to the value 1 is output to the AND circuit 21 for a certain period of time.

When the AND circuit 21 receives the determination signal, it outputs a second switch signal corresponding to a logical value 1 from its output terminal, and the switching transistor Tr6 outputs the voltage of the resistor R28 to its base terminal based on the second switch signal. Is applied. As a result, the switching transistor Tr
6 is turned on (conducted), and a voltage is applied to the capacitor C10 and the resistor R26. Then, the capacitor C1
A voltage is applied to the gate terminal of the thyristor SCR3 from 0 and the resistor R26 to make the thyristor SCR3 conductive. Then, due to the conduction of the thyristor SCR3, the electric charge of the capacitor C9 is discharged, and the right direction indicator Hb1.
A ground fault display drive current as a ground fault direction display signal is output to.

Then, the right direction indicator Hb1 displays the right direction.

On the other hand, when the thyristor SCR3 becomes conductive, the resistance R3
No. 1 voltage switching transistor Tr7 is applied to the base terminal of the switching transistor Tr7.
Turns on (conducts).

Then, the potential of the base terminal of the switching transistor Tr8 drops, and the switching transistor Tr8 turns on. As a result, the capacitor C11 and the resistor R3
A clear control signal is applied to the clear terminal 22 of the IC 14 of the time limit circuit T from 2 and the time constant of the CR circuit.

Then, the time limit circuit T applies the display return signal Sig4 from the Schmitt trigger circuit SC after a certain period of time as in the short-circuit display, and applies a voltage to the capacitor C16 and the resistor R44. As a result, a voltage is applied from the capacitor C16 and the resistor R44 to the gate terminal of the thyristor SCR5,
The thyristor SCR5 becomes conductive. As a result, the electric charge of the capacitor C15 is discharged, and the return drive current is output to the right direction indicator Hb1.

The rightward direction indicator Hb1 is reset by this return drive current and returns to the steady display state.

In addition, when the switching transistor Tr8 is turned on, a gate trigger voltage is applied to the gate terminal of the thyristor SCR6 from the capacitor C11 and the resistor R32 according to the time constant of the CR circuit, and the thyristor SCR6 is turned on. Then, the electric charge of the capacitor C17 is discharged, and the return drive current is output to the left side display Hb2.

At this time, when the left side indicator Hb2 is normally displayed, even if the return drive coil is excited by the return drive current,
Since the magnetic pole portion of the stator has no change in the magnetic pole, the disk continues to maintain the normal display state.

On the contrary, when the left direction indicator Hb2 is in the ground fault direction display state, the magnetic pole portion of the stator has a magnetic pole opposite to that in the normal display state, so the return drive coil is excited by the return drive current. At this time, the magnetic pole portion of the stator is replaced with the magnetic pole, and as a result, the disc is returned to the normal display.

On the contrary, when the phase of the zero-phase current is deviated by 180 to 290 degrees, for example, the phase comparison / determination circuit 11 determines that the ground fault point is on the left side and outputs the determination signal corresponding to the logical value 1 from the left side display output terminal P15 to the AND circuit. 23 is applied for a certain period of time.

Then, when the second switch signal corresponding to the logical value 1 is output from the AND circuit 23, the voltage of the resistor R37 is applied to the base terminal of the switching transistor Tr9 based on the second switch signal. As a result, the switching transistor Tr9 is turned on (conducted),
A voltage is applied to the capacitor C13 and the resistor R35. As a result, a voltage is applied to the gate terminal of the thyristor SCR4 from the capacitor C13 and the resistor R35, and the thyristor SCR4 is made conductive. And thyristor S
Due to the conduction of CR4, the electric charge of the capacitor C12 is discharged, and the ground fault display drive current as the ground fault direction display signal is output to the left direction indicator Hb2.

Then, the left direction indicator Hb2 displays the left direction.

On the other hand, when the thyristor SCR4 becomes conductive, the resistance R4
Since the voltage of 0 is applied to the base terminal of the switching transistor Tr10,
r10 turns on.

Then, the potential of the base terminal of the switching transistor Tr11 drops, and the switching transistor Tr1
1 turns on. Then, the capacitor C14 and the resistor R
A clear control signal is applied to the clear terminal 22 of the IC 14 of the time limit circuit T from 41 and the time constant of the CR circuit.

Then, the time limit circuit T applies the display return signal Sig4 from the Schmitt trigger circuit SC after a certain period of time, as in the short-circuit display, and applies a voltage to the record capacitor C18 and the resistor R46. As a result, a voltage is applied from the capacitor C18 and the resistor R46 to the gate terminal of the thyristor SCR6,
The thyristor SCR6 becomes conductive. Then, due to the conduction of the thyristor SCR6, the electric charge of the capacitor C17 is discharged, and the return drive current is output to the left direction indicator Hb2.

The return drive current resets the left direction indicator Hb2 and returns to the steady display state after a fixed time.

In addition, when the switching transistor Tr11 is turned on, the gate trigger voltage is applied to the gate terminal of the thyristor SCR5 from the capacitor C14 and the resistor R41 according to the time constant of the CR circuit, and the thyristor SCR5.
To turn on. Then, the electric charge of the capacitor C15 is discharged, and the return drive current is output to the right direction indicator Hb1.

At this time, when the right side indicator Hb1 is normally displayed, even if the return drive coil is excited by the return drive current,
Since the magnetic pole portion of the stator has no change in the magnetic pole, the disk continues to maintain the normal display state.

On the contrary, when the right direction indicator Hb1 is in the ground fault direction display state, the magnetic pole portion of the stator has a magnetic pole opposite to that in the normal display state, so that the return drive coil is excited by the return drive current. At this time, the magnetic pole portion of the stator is replaced by the opposite magnetic pole, and as a result, the disk is returned to the normal display. Next, the operation of the power supply voltage check circuit 78 will be described.

When the battery B holds a predetermined voltage, the power supply voltage check display Hc displays a normal state.

In this state, when the voltage of the battery B becomes equal to or lower than the predetermined voltage, the base terminal of the transistor 15 is not applied with the predetermined base voltage, so that the transistor 15 is turned off. Then the inverter I
A signal corresponding to the logical value 1 is input to n2, and based on the signal, the inverter In2 outputs a signal corresponding to the logical value 0 to the knot circuit 25, and the knot circuit 25 outputs the signal corresponding to the logical value 0. A signal corresponding to a logical value 0 is applied to the capacitor C24 and the resistors R65 and R63 based on The AND circuit 26 is a logical value 1 from the CR differentiating circuit.
Input the signal corresponding to the, and logical value 1 based on the signal
Since the signal corresponding to is applied to the base terminal of the switching transistor Tr16, the switching transistor Tr16 is turned on.

As a result, since the display drive current flows through the common terminal 28 and the set terminal 29 of the power supply voltage check display Hc, the drive coil (not shown) is excited, and the mark attached to the back surface of the disc is displayed. It is displayed on the outside to show that the voltage of the battery B has dropped.

The inverter In2 outputs a signal corresponding to the logical value 0 to the knot circuit 32. The knot circuit 32 in the normal voltage display drive circuit 80 outputs a signal corresponding to the logical value 1 to the knot circuit 33 based on the signal corresponding to the logical value 0, and the knot circuit 33 outputs the logical value 0 based on the signal. The signal corresponding to the capacitor C25, resistors R67, R69
Apply to. The AND circuit 34 inputs the signal corresponding to the logical value 0 from the CR differentiating circuit, and based on the signal, outputs the signal corresponding to the logical value 0 to the switching transistor T.
Since the voltage is applied to the base terminal of r17, the switching transistor Tr17 is off.

As described above, when the power supply voltage check indicator Hc indicates that the battery voltage has dropped, it can be confirmed that the battery B has deteriorated. Therefore, the deteriorated battery B is replaced with a new battery B.

When the battery B is replaced with a new battery B, the battery B holds a predetermined voltage, so that the transistor Tr15 is applied with the partial voltage of the resistor R61 at the base terminal and is turned on.
Then, the signal corresponding to the logical value 0 is input to the inverter In2, and the signal corresponding to the logical value 1 is applied to the knot circuit 32 from the inverter In2.

Therefore, the knot circuit 32 outputs a signal corresponding to the logical value 0 to the knot circuit 33 based on the signal corresponding to the logical value 1, and the knot circuit 33 outputs the logical value 1 based on the signal.
The signal corresponding to the capacitor C25, resistors R67, R6
9 is applied. Since the AND circuit 34 inputs the signal corresponding to the logical value 1 from the CR differentiating circuit and applies the signal corresponding to the logical value 1 to the base terminal of the switching transistor Tr17 based on the signal, the switching transistor Tr17 is Turns on.

As a result, the power supply voltage check display Hc has the common terminal 28.
Since the reset drive current flows through the reset terminal 12, the power supply voltage check indicator Hc excites the return drive coil (not shown), so that the mark attached to the surface of the disk is displayed outside and the battery is displayed. It shows that B holds a predetermined voltage value.

In addition, the inverter I in the low voltage display drive circuit 79
When n2 outputs a signal corresponding to the logical value 1 to the knot circuit 25, the knot circuit 25 outputs the signal corresponding to the logical value 0 to the capacitor C2 based on the signal corresponding to the logical value 1.
4, applied to resistors R65 and R63. Since the AND circuit 26 inputs the signal corresponding to the logical value 0 from the CR differentiating circuit and applies the signal corresponding to the logical value 0 to the base terminal of the switching transistor Tr16 based on the signal, the switching transistor Tr16 is It is off.

As described above, in this embodiment, since the forward voltage between the diode arrays Da detected by the current transformer CT is made constant, the battery B is charged with the internal power source type.
No separate power supply required. In addition, whether or not the voltage of the backup battery B is sufficiently charged to supply the drive current to each circuit depends on the operation of the low voltage display drive circuit 79 or the normal voltage display drive circuit 80 of the power supply voltage check circuit 78. Since it is displayed via the voltage check indicator Hc, it is possible to easily determine the time to replace the battery B that is poorly charged due to performance deterioration or the like, and also leave the battery B that is poorly charged to operate the control circuit when a fault current is detected. It is possible to prevent the risk of inviting.

In the third short circuit detection circuit Xc, the diode array Da
Since no voltage is detected by the presence or absence of forward voltage between
Alternatively, it is not necessary to detect the potential between the ground, and therefore there is no fear of the insulation performance.

Further, in the short circuit detection circuit Xc, the photo coupler PC
Since the analog input of the signal based on the short circuit current is intended and the digital output is intended by the photocoupler PC, the resistance value of the resistor R1 can be reduced by the high sensitivity and high speed performance of the phototransistor PTr of the photocoupler PC. It is possible to reduce the heat generation of the resistor R1.

In addition, in the third short-circuit detection circuit Xc, the photocoupler PC can isolate the digital output and the diode array Da connected in series to the short-circuit detection circuit, thereby short-circuiting one current transformer CT. It is possible to connect the detection circuit Xc, the power supply circuit Z, and the no-voltage detection circuit 51.

Further, in the short-circuit detection circuits Xa, Xb, and Xc, the short-circuit indicator Ha is driven for display by discharging the capacitor C6, so that almost no current for driving is consumed.

In this embodiment, the short-circuit indicator Ha and the direction indicator Hb
1, Hb2 are configured by electrically connecting magnetic reversal displays in parallel, so that the circuit impedance is lowered and the capacitors C6 and C used as the driving power source are reduced.
The discharge efficiency of 9, C12, C15, C17 is improved, and display driving is ensured.

Further, since the control circuit uses the IC as described above, there is an advantage that the current consumption of the control circuit can be small.

In addition, since the Schmitt trigger circuit is used for the time limit circuit, it is possible to improve the operational reliability of the reset switching circuit of each display, and also to restore the switching circuit for short-circuit display recovery and ground fault direction display recovery. It is possible to drive a plurality of thyristors in the switching circuit.

Further, in this embodiment, when the right-side direction indicator Hb1 and the left-side direction indicator Hb2 constituting the ground-fault direction indicator are already indicating the ground-fault direction, when the ground-fault further occurs, an old ground fault occurs. Return the fault display to the original normal display state,
The latest ground fault failure display can be performed.

Next, a second embodiment will be described with reference to FIGS. 7 and 8.

This embodiment is largely different from the first embodiment in that the time circuit T is provided with a fault current detection holding circuit 81, an AND circuit 82 as a gate circuit, an oscillation holding circuit 83 and a holding release circuit 84.

Hereinafter, each of the circuits will be described in detail. The same or corresponding components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 7, the fault current detection signal holding circuit 81 outputs a signal corresponding to a logical value 0 from the output terminal of the distribution line L when the distribution line L is in a steady state. When any one of Sig1, Sig2, and Sig3 is input, the signal corresponding to the logical value 1 is continuously output from the output side to the next stage.

Further, when the fault current detection signal holding circuit 81 continuously inputs the signal corresponding to the logical value 1 as described above, when the signal corresponding to the logical value 1 is input from the holding release circuit 84 described later, A signal corresponding to a logical value 0 is output from the output side.

The fault current detection signal holding circuit 81 is specifically as shown in FIG.

That is, the clear control signals Sig1, Sig2, Sig
An OR circuit 86 is connected to the output terminal of the OR circuit 85 for inputting 3
One input terminal of the AND circuit 86 is connected, and the output terminal of the OR circuit 86 is connected to one input terminal a of the AND circuit 87. Further, the output terminal of the AND circuit 87 is an OR circuit 8
6 is connected to the other input terminal 6 and is also connected to one input terminal a of the AND circuit 82. The other input terminal of the AND circuit 87 is connected to the output terminal of the AND circuit 93 of the holding release circuit 84 described later via the inverter In10.

The OR circuit 86, the AND circuit 87, and the impedance 10 form a fault current detection signal holding circuit 81.

The other input terminal b of the AND circuit 82 is connected to the output terminal of the inverter In1 of the no-voltage detector.

Next, as shown in FIG. 7, the oscillation holding circuit 83 outputs the signal corresponding to the logical value 1 based on the signal corresponding to the logical value 0 when the AND circuit 82 outputs the signal corresponding to the logical value 0. When the AND circuit 82 outputs a signal corresponding to the logical value 0 → 1, a signal corresponding to the logical value 1 → 0 is output based on the signal to the next stage. To the IC 14 to start oscillation.

The oscillation holding circuit 83 outputs the signal corresponding to the logical value 0 as described above, while the holding release circuit 8 to be described later is provided.
When a signal corresponding to the logical value 1 is input from 4, the signal corresponding to the logical value 1 is output from the output side.

Specifically, the oscillation holding circuit 83 is as shown in FIG.

That is, the output terminal of the AND circuit 82 is the OR circuit 8
8 is connected to one input terminal of the AND circuit 88, and the output terminal of the OR circuit 88 is connected to one input terminal of the AND circuit 89. The other input terminal of the AND circuit 89 has an inverter I
It is connected to the output terminal of an AND circuit 93 of a holding release circuit 84 described later through n11. The output terminal of the AND circuit 89 is connected to the IC 14 via the knot circuit 90.
It is connected to the clear terminal 22 of.

The OR circuit 88, the AND circuit 89, the knot circuit 90 and the inverter In11 constitute an oscillation holding circuit 83.

Further, one input terminal of the NAND circuit 91 is connected to the output terminal of the IC 14, and the other input terminal of the NAND circuit 91 is connected to the series circuit of the resistors R100, R101 and the inverter In12, and the positive terminal of the resistor R101. A capacitor C100 is connected between the ground line E and the ground line E. The output terminal of the NAND circuit 91 is an inverter I
n13 through diodes D8, D23, D2, respectively.
It is connected to the gate terminals of thyristors SCR1, SCR5 and SCR6 via 8.

The IC 14, the resistors R50 and R51, the capacitor C2
0, the NAND circuit 91, the resistors R100 and R101, the capacitor C100, and the inverters In12 and In13 form a time circuit T. The IC 14 starts the oscillation of the oscillation circuit 74 when the signal corresponding to the logical value 0 is inputted from the oscillation holding circuit 83. Then, when the signal corresponding to the logical value 1 is output from the IC 14 after a predetermined time, one pulse signal corresponding to the logical value 0 is output from the NAND circuit 91, whereby the display return signal Sig is output from the inverter In13.
A signal corresponding to a logical value of 1 is output as 4, and a gate trigger voltage sufficient to turn on the thyristor is applied to the gate terminals of the thyristors SCR1, SCR5 and SCR6.

Next, the hold release circuit 84 outputs a signal corresponding to a logical value of 0 from the output side of the fault current detection hold circuit 81 and the oscillation hold circuit 83 while the IC 14 continues the oscillation stop state.
It is designed to output to. Further, the inverter I
When a signal corresponding to the logical value 1 is input from n13, the signal corresponding to the logical value 1 is output from the output side thereof.

Specifically, the holding release circuit 84 is as shown in FIG. That is, the output terminal of the inverter In13 is connected to the input terminal of the AND circuit 92, and the output terminal of the AND circuit 92 is connected to the output terminal of the AND circuit 93 via the series circuit of the resistors R102 and R103.
Also, a series circuit of a resistor R104 and a diode D100 is connected in parallel to both terminals of the resistor R102, and a resistor R1
The negative terminal of 02 is connected to the ground wire E via a capacitor C101.

The AND circuits 92 and 93, the resistors R102 and R103,
R104, diode D100 and capacitor C101
The hold canceling circuit 84 is constituted by and.

A series circuit of a diode D101 and a capacitor C102 is connected between the emitter of the transistor Tr14 of the power supply circuit Z and the negative terminal of the full-wave rectifier 6 via a resistor R105, and the positive terminal of the capacitor C102 is connected to the fault current detection signal. By being connected to each circuit of the holding circuit 81, the capacitor C102 serves as a power source of the fault current detection signal holding circuit 81. And this capacitor C1
Even if the distribution line L is in a no-voltage state by 02, a voltage is applied to the same fault current detection signal holding circuit 81.

In this embodiment, the capacitor C103 is used instead of the battery B of the first embodiment.

In the short-circuit ground fault direction detection display device configured as described above, when the distribution line L is in a steady state, the inverter In1 of the no-voltage detection unit outputs a signal corresponding to the logical value 1, and as a result, the AND circuit. A signal corresponding to the logical value 1 is input to the input terminal b of 82. That is, the AND circuit 82 inputs a signal corresponding to the logical value 1 to the input terminal b and inputs a signal corresponding to the logical value 0 to one input terminal a of the AND circuit 82. The signal corresponding to 0 is output to the next stage.

Since the oscillation holding circuit 83 inputs the signal corresponding to the logical value 0, it outputs the signal corresponding to the logical value 1 to the clear terminal 22 of the IC 14 from its output side.
The IC 14 continues the oscillation stopped state.

Next, for example, a short-circuit fault in which the substation breaker can trip occurs in the distribution line L. As a result, the short-circuit indicator Ha is displayed as in the case of the first embodiment, and the voltage amplifier circuit 65 outputs an OR signal correspondingly. Clear control signal S via circuit 85
When the fault current detection signal holding circuit 81 inputs ig1,
The signal corresponding to the logical value 1 is continuously output from the output side to the input terminal a of the AND circuit 82. When the substation circuit breaker trips due to the short-circuit fault and the distribution line L is in a no-voltage state, the inverter In1 of the no-voltage detection unit outputs a signal corresponding to a logical value 0, and the AND circuit 82 inputs the input terminal b. A signal corresponding to the logical value 0 is input to.

That is, since the AND circuit 82 inputs the signal corresponding to the logical value 1 to the input terminal b, the AND circuit 82 outputs the signal corresponding to the logical value 0 to the oscillation holding circuit 83. Furthermore, if the re-transmission of the substation to the distribution line L succeeds,
Since the signal corresponding to the logical value 1 is output from the inverter In1 of the no-voltage detecting unit, as a result, the signal corresponding to the logical value 1 is input to the input terminal b of the AND circuit 82,
That is, since the signal corresponding to the logical value 1 is input to the AND circuit 82, the AND circuit 82 outputs the signal corresponding to the logical value 1 to the oscillation holding circuit 83.

As a result, since the signal corresponding to the logical value 0 → 1 is input from the AND circuit 82 to the oscillation holding circuit 83, the oscillation holding circuit 83 outputs the signal corresponding to the logical value 1 → 0 of the IC 14 based on the signal. Output to clear terminal 22 and oscillate circuit 74
To oscillate.

When a predetermined time has elapsed, the IC 14 outputs a signal corresponding to the logical value 1 from its output terminal. As a result, the NAND circuit 91 outputs one pulse signal corresponding to the logical value 0, and thereby the inverter In13 outputs the signal corresponding to the logical value 1 as the display restoration signal Sig4, and the thyristor SCR1 has its gate terminal connected to the thyristor SCR1. SC
A sufficient gate trigger voltage is applied so that R1 is turned on, and the short-circuit indicator Ha is restored to display as in the first embodiment.

Further, at the same time, when the holding release circuit 84 inputs a signal corresponding to the logical value 1 from the inverter In13, the holding release circuit 84 outputs a signal corresponding to the logical value 1 from the output side thereof based on this signal. It outputs to the holding circuit 81 and the oscillation holding circuit 83. Then, the fault current detection signal holding circuit 81 outputs the signal, while the oscillation holding circuit 8
3 outputs a signal corresponding to the logical value 1 based on the signal. As a result, the IC 14 stops the oscillation of the oscillator circuit 74. That is, the fault current holding circuit 81 and the oscillation holding circuit 83 return to their original states.

Even when a ground fault occurs in the distribution line L that allows the substation breaker to trip, each circuit operates in the same manner as the short circuit fault.

Further, when the distribution line L is short-circuited, the substation circuit breaker trips for a reason other than the fault current, and a voltage is lost, and after that, the power is successfully retransmitted to the distribution line L. Then, the AND circuit 82 is connected to the input terminal b. A signal corresponding to the logical value 1 → 0 → 1 is input by the no-voltage detector. However, the fault current detection signal holding circuit 81 has clear control signals Sig1, Sig2, S
Since ig3 is not input, the failure current detection signal holding circuit 8
The output side of 1 outputs the signal corresponding to the logical value 0 as in the steady state of the distribution line L, and therefore the AND circuit 82 outputs the signal corresponding to the logical value 0, whereby the oscillation holding circuit 8
3 outputs a signal corresponding to the logical value 1,
Indicates that the oscillation is still stopped.

As described above, in the second embodiment, the IC 14 is operated by the timer under the signal output according to the AND condition of the fault current and the voltageless condition of the distribution line L, and the AND condition when the substation re-transmits power. The oscillation of the oscillation circuit 74 is stopped by the signal output from the IC 14.

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

Other Embodiments In the first embodiment, the input terminal of the AND circuit 21 as the second gate circuit in the drive section of the ground fault direction indicator is connected to the right side display output terminal P14 of the phase determination circuit 20,
Further, the input terminal of the AND circuit 23 as the second gate circuit is connected to the left side display output terminal P15 of the phase discrimination circuit 20, and the AND circuits 21 and 23 are further connected.
The non-voltage detection circuit 51 may be connected to the input terminal of the above through the second waveform operation circuit 52 similarly to the drive unit of the short-circuit indicator.

In this case, the AND circuits 21 and 23 are operated by the non-voltage detecting section composed of the non-voltage detecting circuit 51 and the second waveform operating circuit 52 while the determination signal from the phase comparison / determining circuit 20 is being applied. When the non-voltage detection signal is applied, the second switch signal corresponding to the logical value 1 is output.

Therefore, in this case, the ground fault direction indicators Hb1 and Hb2 display the ground fault direction only when the distribution line L has a ground fault and the circuit breaker of the substation trips due to the ground fault. Become.

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

It should be noted that the present invention is not limited to the above embodiment, and for example, in the above embodiment, the battery B of the power supply circuit Z is
Alternatively, a high capacity capacitor may be used. In that case, the power supply voltage check circuit 78 can be used as a voltage check for the capacitor.

As described above in detail, according to the present invention, the drive current for the backup can be supplied to the control circuit even when the backup drive power supply is cut off, and the control circuit can be normally operated when the voltage of the backup drive power supply is cut off. Whether or not the battery is charged enough to operate can be easily determined by the display contents of the power supply voltage check display, so there is no mistake in the replacement time of the backup drive power supply with poor charging due to performance deterioration, etc. There is an effect that it is possible to prevent the possibility that the control circuit will malfunction when a faulty current is detected by leaving the backup drive power source with poor charging left unattended.

[Brief description of drawings]

FIG. 1 is a schematic view of a short-circuit ground fault direction detection display device according to an embodiment of the present invention, and FIG. 2 is an electric block circuit diagram of the short-circuit ground fault direction detection display device. Electric block circuit diagram other than the circuit, (b) is an electric block circuit diagram of the time circuit, FIG. 3 is an electric circuit diagram of the short-circuit ground fault direction detection display device, FIG. 4 is a schematic diagram of the short-circuit indicator, the fifth FIG. 6 is an explanatory view for showing the same operation, FIG. 6 is an electric circuit diagram of a short-circuit indicator, FIG. 7 is an electric block circuit diagram of essential parts of the second embodiment, and FIG. 8 is a block diagram of FIG. It is the converted electric circuit diagram. 1 ... Short-circuit ground fault direction detection display device, 2 ... Zero-phase current transformer,
3 ... Zero phase voltage detector, 6 ... Full wave rectifier, 8 ... 1st AND circuit (1st waveform operation circuit), 9 ... 2nd AND circuit (1st gate circuit), 13 ... Knot circuit, 14 ... I
C, 20 ... Phase comparison / determination circuit, 21, 23 ... AND circuit (second gate circuit), 25 ... Not circuit, 26 ... AND circuit, 32, 33 ... Not circuit, 34 ... AND circuit,
51 ... No-voltage detection circuit, 52 ... Second waveform manipulation circuit, 5
5 ... 1st switching circuit, 57 ... Short circuit indicator restoration switching circuit, 68, 73 ... Ground fault direction indicator restoration switching circuit, 65, 70 ... Second switching circuit, 78 ... Power supply voltage check circuit, 79 ... voltage drop display drive circuit, 80 ... voltage normal display drive circuit, Xa ... first short circuit detection circuit, Xb ... second short circuit detection circuit, Xc ... third short circuit detection circuit, Z ... power supply circuit, T ... time limit Circuit, Ha ...
Short-circuit indicator, Hb1 ... right direction indicator, Hb2 ... left direction indicator, Hc ... power supply voltage check indicator, CT1 ... first current transformer, CT2 ... second current transformer, CT3 ...
Third current transformer, L ... Distribution line.

Front Page Continuation (72) Inventor Katsunori Aoki No. 1 Upper Needle, Inayama City, Aichi Prefecture Takamatsu Electric Works (72) Inventor Mitsuharu Kutomi No. 1 Upper Needle, Inuyama City, Aichi Takamatsu Electric Works Co., Ltd. (56 ) References Japanese Patent Laid-Open No. 58-18173 (JP, A) Actually developed 53-27433 (JP, U)

Claims (1)

[Claims] 1. A failure detection display device for displaying a failure by a control circuit based on a detection signal detected by a detector when a failure current flowing through a distribution line is detected. A backup drive power supply for supplying drive current is connected to the backup drive power supply, and when the voltage of the backup drive power supply is maintained at a predetermined voltage, a drive circuit for displaying a normal voltage of the power supply voltage is displayed normally, and the backup And a voltage drop display drive circuit for driving a power supply voltage check display device to a low voltage display when the voltage of a drive power supply for the device drops below a predetermined voltage.