JPH0638692B2 - Ground fault direction relay and equipment - Google Patents

Description

Detailed Description of the Invention A. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground fault direction relay device formed by connecting a plurality of ground fault direction relays, and particularly to a ground fault direction relay device in which the number of connectable relays is dramatically increased.

B. SUMMARY OF THE INVENTION The present invention is a ground fault direction relay device formed by connecting a plurality of ground fault direction relays, in which a zero phase voltage signal sent from a zero phase voltage signal generator to each local fault direction relay is always at a high level (hereinafter , H level) to a low level (hereinafter, referred to as L level) pulse-like signal, miswiring of signal lines can be easily identified, and the number of connectable units is dramatically increased. A technique for supplying a ground fault direction relay device that improves a noise margin is disclosed.

C. 2. Description of the Related Art A ground fault direction relay detects a zero-phase voltage and a zero-phase current when a ground fault occurs and compares the phases of these voltage and current, and the fault detects a zero-phase current transformer. It is a relay that determines the direction of the power supply side or the load side at the boundary and performs protection operation in case of a ground fault on the load side. Then, the ground fault direction relay device is generally arranged by serially arranging a plurality of ground fault direction relays in series from the upper stage on the power supply side of the distribution line to the lower side of the load to detect a ground fault accident in each section. Then, the load side of the distribution line in which the accident occurred is cut off, and the protective operation is performed so as not to affect the healthy section on the power source side.

FIG. 4 is a circuit diagram showing an example of such a conventional ground fault direction relay device. In FIG. 4, 1 is a transformer on the power supply side, 2 is a circuit breaker, 3 is a ground fault direction relay arranged on the power supply side, and 4, 5, 6, 7 and 8 are arranged on distribution lines. Circuit breakers 9, 10, 11, 12, and 13 are zero-phase current transformers arranged on the load side of the circuit breakers 4, 5, 6, 7, and 8, 14, 15, 16, 17, and 18 are A ground fault direction relay connected to the zero-phase current transformers 9, 10, 11, 12 and 13. This ground fault direction relay 14,15,16,1
7 and 18 are sequentially arranged in series from the power source side shown in the upper part of the drawing to the load side shown in the lower part of the drawing, and the circuit breakers 4, 5,
A cutoff command is given to 6, 7, and 8. Reference numeral 20 denotes a zero-phase voltage signal generator, which converts the zero-phase voltage V ₀ from the zero-phase voltage detector 19 into a pulse-shaped zero-phase voltage signal V ₁ and common signal lines m and n.
And is applied in parallel to the ground fault direction relays 14, 15, 16, 17 and 18 via.

Here, for example, when a ground fault occurs at point E on the load side of the zero-phase current transformer 11, a zero-phase current flows through the zero-phase current transformers 9 to 11, and at the same time, the zero-phase voltage detector 19 receives the zero-phase current. The voltage V ₀ is generated, the zero-phase voltage signal generator 20 outputs the zero-phase voltage signal V ₁ , which are input to the local fault direction relay, and E
The relays 14 to 16 located on the power source side of the point are about to operate. In this case, it is preferable that only the relay 16 on the power source side closest to the point E of the ground fault operates to shut off the circuit breaker 6 and not affect the distribution line on the power source side. There is a cooperation in the operation time among the eighteen. In consideration of the breaking time of the circuit breaker, the coordination of the operating time is generally performed from the ground fault relay 16 on the lower side to the relays 15, 14 on the upper stage, for example, 0.2 seconds, 0.5 seconds, 0 seconds. ．
When 8 seconds and the operating time are sequentially set to be long, and the ground fault direction relay 16 on the lower side operates, the circuit breaker 6 is shut off to disconnect the distribution line on the lower stage from the point E, but the ground fault direction relay on the upper stage side 15
And 14 are disabled.

Actually, in order to configure the ground fault direction relay device as shown in FIG. 4, any one of the plurality of ground fault direction relays connected to the zero phase current transformer is a zero phase relay. It is usually formed integrally with the voltage signal generator 20. Fig. 3
(a) is a required partial configuration diagram showing an example of such a type of ground fault direction relay, and FIG. 3 (b) shows an example of another ground fault direction relay used as the load side relays 15-18. It is a partial block diagram. In both figures, P1 and P2 are AC110v
, M and N are signal terminals, Z1 and Z2 are input terminals for the zero-phase current detected by the zero-phase current transformer, and Y1 and Y2 are also input terminals for the zero-phase voltage. is there. Further, 21 and 22 are filters, 23 and 24 are waveform shaping, 25 and 26 are amplifiers, 27 and 28 are level detection,
Reference numeral 29 is a signal output, 30 is a signal input, 31 is a power supply, 32 is a time limit circuit, and 33 is a test switch.

When a ground fault occurs here, the zero-phase current I ₀ detected by the zero-phase current transformer is supplied to the input terminals Z1 and Z2, and the simultaneously generated zero-phase voltage V ₀ is supplied to the input terminals Y1 and Y2. To be done. The zero-phase current I ₀ passes through the film circuit 21, is further amplified by the amplifier 25 and level-detected by the level detection circuit 27, and is then input to the AND gate 34. At the same time, the zero-phase voltage V ₀ supplied to the input terminals Y1 and Y2 similarly passes through the film circuit 22, the amplifier 26, and the level detection circuit 28, and then is input to the other AND gate 36. On the other hand, the zero-phase current I ₀ and the zero-phase voltage V ₀ are shaped into rectangular and pulse shapes by the waveform shaping circuits 23 and 24 as shown in FIG. 7, and the shaped signals I ₁ and V ₁ are respectively shaped. When the currents I ₀ and V ₀ are input to the AND gates 34 and 36 and become higher than a set level, the waveform-shaped I ₁
And V ₁ are output from the AND gates 34 and 36 and input to the AND gate 35, phase comparison is performed in the AND gate 35, and in the case of another distribution line ground fault, as shown in FIG. No output is output, and if there is a ground fault in the distribution line,
As shown in FIG. 7 (b), when the AND condition is satisfied, the time limit circuit 32
The output signal is output to and the circuit breaker is shut off after a certain period of time.

On the other hand, of the waveform-shaped signals, the zero-phase voltage signal V ₁
Is output from the signal terminals M and N by the signal output circuit 29 (solid line arrow) and is transmitted to the common signal lines m and n in FIG. 4 to be transmitted to another ground fault direction relay (FIG. 3 (b)). It is input to the signal terminals M and N. Therefore, the other ground fault direction relays 15 to 18 do not need the zero-phase voltage signal generation circuit.

D. However, in the above-mentioned conventional device, the zero-phase voltage signal supplied from the zero-phase voltage signal generator or the relay having the signal generator is H level as shown in FIG. Alternatively, it is formed by a pulse rising from the L level side to the H level side between two voltage levels of L. That is, FIG. 5 is a circuit for generating the zero-phase voltage signal V ₁ of the ground fault direction relay 14 including the zero-phase voltage signal generator 20 in FIG. 4 and each of the other relays 15 and 16 having the zero-phase voltage signal. is a block diagram showing an example of conventional connection circuit receiving the signal V _1. In the conventional ground fault direction relay device, as shown in FIG. 5, the ground fault direction relay 14
The zero-phase voltage signal V ₁ output from the side of the transistor is on the emitter side 14b of the transistor with reference to the L level output voltage 14a.
The signal of the H level pulse which is output from is formed and is supplied to the base sides 15a and 16a of the transistors arranged in the other ground fault direction relays 15 and 16, so that the output of the ground fault direction relay 14 of Due to the power source power, the load side ground-fault direction relay could only supply signals up to 20 units. Further, since the input of the signal V ₁ is the transistor input, as shown in FIG. 6, the noise n1 of about 0.6v or less which is the on-voltage of the transistor is canceled,
For noise of about 0.6 V or more, the transistor is turned on, and the noise n2 is regarded as the signal S1 of the voltage V ₁ and malfunctions.

The present invention was devised in view of such problems, and an object thereof is to provide a ground fault direction relay device capable of dramatically increasing the number of connectable units and improving a noise margin. To do.

E. Means for Solving Problems In the present invention, means for solving the above problems include a zero-phase voltage detector for detecting a zero-phase voltage and a zero-phase current when a ground fault occurs. The zero-phase current transformer is connected to these zero-phase voltage detector and zero-phase current transformer, and the phases of these voltages and currents are compared. Side-to-side ground fault direction relays, a circuit breaker that shuts off the load side of the distribution line where a ground fault occurred due to a ground fault direction relay command, and a pulsed zero-phase voltage In a ground fault direction relay device composed of a zero-phase voltage signal generator that is converted into a signal and given to the local fault direction relay, a zero-phase voltage signal sent from the zero-phase voltage signal generator to the local fault direction relay is constantly Make a negative pulse signal from H level to L level The ground fault direction relay is a ground fault direction relay device configured to obtain a pulsed outflow signal V ₁ ′ in the form of current output from the pulse signal in the negative direction and thereby generate a zero-phase voltage signal. It is a thing.

F. Action In the present invention, the zero-phase voltage signal is based on the H level side and L
As an inhalation type that supplies current from the relay on the receiving side to the relay on the transmitting side by forming a pulse on the level side,
It is possible to eliminate the current burden on the relay on the transmission side and operate the relay by connecting it to the receiving side up to the number within the range allowed by the collector current of the connecting transistor.

G. Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of a zero-phase voltage signal circuit of a ground fault relay device embodying the present invention. The ground fault direction relay device of the present embodiment has the same configuration as the general example shown in FIG. 4, and the zero-phase voltage signal generator 20 may be provided independently as shown in FIG. Alternatively, it may be built in the ground fault direction relay 14. FIG. 1 is a circuit diagram for transmitting the zero-phase voltage signal V ₁ from the built-in zero-phase voltage signal generator 20 to the other ground fault direction relays 15 and 16. For example, on the ground fault direction vertical electric device 14 side, In the signal output circuit 29 of FIG.
The 6 side is provided in the signal input circuit 30 of FIG. 3 (b).

In FIG. 1, the signal line from the zero-phase voltage signal generator is
It is connected to the collector side 14a of the transistor and forms a negative pulse with respect to the H level reference voltage 14b connected to the emitter. Therefore, when a pulsed V ₁ is applied between the base and emitter of the transistor, it becomes an L level signal as shown in FIG. 2, and the current flows from the other ground fault direction relays 15 and 16 via a common signal line. It will flow to the relay 14 side. That is, on the side of the zero-phase voltage signal generation circuit, the transistor T is connected to the circuit shown in FIG.
When the zero-phase voltage signal V ₁ is applied between the base and the emitter of the transistor T, it becomes L level and the outflow signal V ₁ ′ flows from the terminals M and N as indicated by the dotted arrow. Further, from the other local relay direction relay side, an outflow signal V ₁ ′ flows out from the signal input circuit 30 as shown by a dotted arrow as shown in FIG. 3 (b). Note that the AND gate 35 when the signal input circuit 30 flows out signal V ₁ at 'flows out so that V ₁ signal of FIG. 7 comes out.

The ground-fault direction relays 15 and 16 are not transistors as in the conventional example, but are pulse-shaped ground-fault voltage phase signals in the form of unidirectional current output from the input end 15a or the like, via the resistor R and the diode D. The outflow signal V ₁ ′ will be obtained.
Due to this outflow, the anode side of the diode becomes L level, so that the switching circuit A causes the light emitting diode LE.
The L side of the D side of the cathode becomes the light emitting diode L.
The ED is turned on.

In the present invention, as shown in FIG. 1, a zero-phase voltage signal forms a pulse on the L level side to supply a current from the receiving side to the transmitting side relay, and the current burden on the transmitting side relay is eliminated. It is possible to connect and operate the relays on the receiving side up to the number of transistors within the range allowed by the collector current of the transistor.

For example, if the collector current of the transistor on the relay 14 side is 500 mA, and the signal current from the relays 15 and 16 on the receiving side is 0.25 mA, then 500 mA / 0.25 mA = 2000 units, and up to 2000 units can be connected and operated. It is possible. Also, the relays 15 and 16 on the receiving side have a power supply voltage of 1
Since / 2 becomes the threshold value, if the power supply voltage is 12v, for example, noise of 6v or less can be ignored, and the noise margin is dramatically improved as compared with 0.6v of the conventional example.

Further, since the common signal line shown in FIG. 4 is laid for a considerable long distance, it is difficult to distinguish between m and n. Therefore, when the signal lines m and n are connected to the terminals M and N of the local relay, it is very easy for miswiring to occur, and it is difficult to find them. The logic of the signal is reversed and the signal V1 is displayed at all times when no ground fault has occurred, and for example, the light emitting diode LED is continuously lit, so that miswiring is immediately identified.

H. Effects of the Invention As described above, according to the present invention, the number of connectable units is dramatically increased by an extremely simple circuit improvement,
In addition, it is possible to improve the noise margin, and it is possible to provide an extremely excellent ground fault direction relay device in which miswiring of signal lines can be easily identified.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a connection circuit of the present invention, FIG. 2 is a waveform diagram thereof, FIG. 3 is a configuration diagram of a relay, and FIG. 4 is a configuration diagram of a general example of a ground fault direction relay device. FIG. 5 is a configuration diagram of a conventional example, FIG. 6 is a waveform diagram of the conventional example, and FIG. 7 is a waveform diagram for explaining the operation of the ground fault direction relay. 1 ... Transformer, 2, 4-8 ... Circuit breaker, 3, 14-18
...... Ground fault relay, 9 to 13 ...... Zero-phase current transformer, 19 ...
... zero phase voltage signal generator, V ₀ ... ground fault voltage phase signal.

Claims (3)

[Claims] 1. A zero-phase current is input and the waveform is shaped into a zero-phase current signal, and the waveform-shaped zero-phase voltage signal is received from an external zero-phase voltage signal generator. In the ground fault direction relay which determines the ground fault direction by comparing the phases of both the current signal and the zero phase voltage signal, and outputs an output signal when the ground fault is on the load side, the zero phase voltage signal generation The signal from the generator is received as a pulse in the negative direction, and a pulse-shaped outflow signal in the form of current output is output to the zero-phase voltage signal generator in response to the pulse in the negative direction. A ground fault direction relay having a signal input circuit for generating a voltage signal. 2. The signal input circuit is configured to output a signal through a series circuit of a resistor and a diode having an anode side connected thereto, and to turn on a light emitting diode when the anode side becomes a low level. The ground fault direction relay according to claim 1, wherein 3. A plurality of ground fault direction relays are arranged from a power supply side upper stage to a load side lower stage of the distribution line, and the zero phase voltage and the zero phase current detected from the distribution line are pulsed to these local fault direction relays. The zero-phase voltage signal and the zero-phase current signal are applied to determine the ground fault direction by comparing the phases of these two signals, and when the ground fault is on the load side, a cutoff command signal is issued to perform the protective operation. In the ground fault direction relay device, the zero-phase voltage signal is obtained from a zero-phase voltage signal generator via a common signal line and is given to the local fault direction relay, and the zero-phase voltage signal is also applied. The generator is provided with a signal output circuit that always forms a negative pulse from the high level side to the low level side when the zero-phase voltage signal is input and gives it to the common signal line, and the local fault direction relay. The signal output When the output of the output circuit becomes low level, a pulsed outflow signal in the form of current output is made to flow out to the signal output circuit via the common signal line, and a high level zero-phase voltage signal is generated when this current flows out. A ground fault direction relay device, which is provided with a signal input circuit.