JPH06105451A - Line protection relay device - Google Patents

Abstract

PURPOSE:To detect, in a high detection sensitivity, the accident occurring in the line including a transmission line and a branching line thereof within the protection object section under the condition that there is no input of an external accident detecting signal when an internal accident detection signal is inputted. CONSTITUTION:When an internal accident occurs at the accident point F1, a trip allowable output signal is outputted from a current differential decision part 104 and it is also outputted from a voltage relay 105. Thereby, a cut-off command signal is outputted from an AND gate 107 and the breakers 41, 42 are tripped. Meanwhile, even when the trip allowable output signal is outputted from the current differential decision part 104 by an accident in the area outside the protection object section, the condition of logical AND of the AND gate 107 is not satisfied and the cut-off command signal is not outputted. As explained, since whether an accident has occurred or not in the protection object area is decided based on the condition of electrical signal of the transmission line 11 and the signal from the direction relays 300, 400, an accident in the protection object area can be detected with a high sensitivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line protection relay device, and more particularly to a line protection relay device suitable for protecting a transmission line and a line including a branch line branched from the transmission line in a protection target section.

[0002]

2. Description of the Related Art Generally, in a 77 kV system or a system of 66 kV or less among power transmission systems, there is a case where a branch line directly branching from the middle of a main power transmission line to receive power for private use. In such a system, circuit breakers, current transformers, and main relays are installed at the electrical stations on both ends of the main power transmission line, and the current signal detected by the current transformer is converted into a digital signal, and this digital signal is converted into a digital signal. A configuration is adopted in which the pulse codes are mutually transmitted between electric stations, and when the deviation between the two exceeds a set value, the circuit breaker is tripped because an accident has occurred in the protected area.

However, when a branch line is connected to the main power transmission line, it is difficult to detect an accident from the deviation of the current signal detected at each electric station. That is, when the inrush current flows through the load of the branch line due to the reclosing or the like, the influence of this current appears in the current of the main power transmission line, and there is a possibility that the inrush current may erroneously determine that an accident has occurred.

Therefore, if the electric current of the branch line is detected at the electric station connected to the branch line and the information of the detected current itself is transmitted to the electric station of the main power transmission line through the transmission line, the inrush current causes an error. It is possible to prevent the determination.

However, in the electric station provided on the branch line,
Usually, since there is no facility for transmitting a current signal, an ideal current differential determination may not be possible at an electric station of a main transmission line including a branch line.

[0006] Therefore, as a method of protecting a line accompanied by a branch line, the 1st year conference of the Institute of Electrical Engineers of Japan, No. 1306 and 1991 National Conference of the Institute of Electrical Engineers of Japan No. What has been described in 1409 is proposed.

[0007]

However, in the above-mentioned prior art, in order to prevent malfunction of the transformer connected to the branch line due to the magnetizing inrush current or an external accident (a accident behind the branch line electric station), It is configured to reduce the current differential determination sensitivity of the main relay installed at the electric station of the distribution line, and there is a risk that accidents within the protected area may not be reliably detected.

An object of the present invention is to provide a line protection relay device capable of highly sensitively detecting an accident in a line including a power transmission line and a branch line branched from this power transmission line in a section to be protected. .

[0009]

In order to achieve the above object, the present invention provides, as a first device, a section of a line connecting a circuit breaker among circuit lines of a transmission line connected to a power source. In a line protection relay device in which a section of a line connecting a branch point and a circuit breaker in the branch line of a branch line branched from the power transmission line is a protection target section, an electric signal of the power transmission line is taken in Internal accident detection means that outputs an internal accident detection signal when a state change corresponding to an accident in the protection target section is detected, and an electric signal of the branch line is taken in and an accident outside the protection target section is obtained from this electric signal. External accident detection signal that outputs an external accident detection signal when a state change equivalent to the above is detected, and an external accident detection signal is input when the internal accident detection signal and the external accident detection device output are received. It is obtained by constituting the line protection relay apparatus characterized by comprising a circuit breaker trip unit to trip the circuit breaker in the power line on condition that there is no input signal.

As a second device, a section of a line connecting a circuit breaker and a circuit breaker in a line of a power transmission line connected to a power source and a branch point and a middle of a branch line of a line of a branch line branched from this power transmission line. In a line protection relay device in which a section of the line connecting the circuit breaker is a protection target section, when an electric signal of the transmission line is captured and a state change corresponding to an accident in the protection target section is detected from the electric signal, A main internal accident detection means that outputs an internal accident detection signal, and an electric signal of the branch line are taken in and an internal accident detection signal is output when a state change corresponding to an accident in the protection target section is detected from this electric signal. The transmission line is provided on condition that the auxiliary internal accident detection means receives the output of the main internal accident detection means and the output of the auxiliary internal accident detection means and receives the internal accident detection signal from each internal accident detection means. It is obtained by constituting the line protection relay device according to claim that a circuit breaker trip unit to trip the circuit breaker.

As a third device, a section of a line connecting a circuit breaker and a circuit breaker in a line of a power transmission line connected to a power source and a branch point of the line of a branch line branched from the power transmission line and the middle of the branch line. In a line protection relay device in which a section of a line connecting the circuit breaker is a protection target section, a pair of current detection means for detecting currents at both ends of the power transmission line, and a deviation of detected current of each current detection means Current deviation calculation means for calculating, internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and auxiliary for detecting current on the terminal side of the branch line. Current detection means, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, detection output of the auxiliary current detection means and detection output of the auxiliary voltage detection means are fetched from these detection outputs outside the protected area. Thing External accident detection signal output means for outputting an external accident detection signal when it is detected that the internal accident detection signal output means outputs the internal accident detection signal output means and the external accident detection signal output means output signal. And a circuit breaker trip means for tripping a circuit breaker in the transmission line on condition that no external accident detection signal is input.

As a fourth device, a section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, and a branch point and a middle of a branch line among lines of a branch line branched from this power transmission line. In a line protection relay device in which a section of a line connecting the circuit breaker is a protection target section, a pair of current detection means for detecting currents at both ends of the power transmission line, and a deviation of detected current of each current detection means Current deviation calculation means for calculating, main internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and the current on the terminal side of the branch line is detected. Auxiliary current detection means, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, detection output of the auxiliary current detection means and detection output of the auxiliary voltage detection means, and these detection outputs within the protection target section so Auxiliary internal accident detection signal output means for outputting an internal accident detection signal when it is detected that a failure has occurred, and an output signal of the main internal accident detection signal output means and an output signal of the auxiliary internal accident detection signal output means. A circuit protection relay device comprising: a circuit breaker trip means for tripping a circuit breaker in the power transmission line on condition that an internal accident detection signal is inputted from the internal accident detection signal output means. It was done.

As a fifth device, a section of the line connecting the circuit breaker and the circuit breaker among the lines of the power transmission line connected to the power source and the branch point and the middle of the branch line among the lines of the branch line branched from this power transmission line. In a line protection relay device in which a section of a line connecting to the circuit breaker is a protection target section, a pair of current detection means for detecting currents at both ends of the power transmission line, and detected currents of the respective current detection means are main data. A current deviation calculating means for taking in via a transmission line and calculating a deviation between the two; an internal accident detection signal outputting means for outputting an internal accident detection signal when the calculated value of the current deviation calculating means exceeds a set value; Auxiliary current detection means for detecting the current on the terminal side of the line, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, and the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means. External accident detection signal output means for outputting an external accident detection signal when it is detected from the detection output of the above that an accident has occurred outside the protection target section, and an external accident detection while receiving the output signal of the internal accident detection signal output means. Circuit breaker trip means for receiving the output signal of the signal output means through the auxiliary data transmission line and tripping the circuit breaker in the power transmission line on condition that no external accident detection signal is input when the internal accident detection signal is input The line protection relay device is characterized in that

As a sixth device, a section of the line connecting the circuit breaker and the circuit breaker among the lines of the power transmission line connected to the power source and the branch point and the middle of the branch line among the lines of the branch line branched from this power transmission line. In a line protection relay device in which a section of the line connecting the circuit breaker is a protection target section, when an electric signal of the transmission line is captured and a state change corresponding to an accident in the protection target section is detected from the electric signal, An internal accident detection means for outputting an internal accident detection signal, and an external accident detection signal which takes in an electric signal of the branch line and outputs an external accident detection signal when a state change corresponding to an accident outside the protected section is detected from the electric signal Receives the output of the accident detection means, the output of the internal accident detection means and the output of the external accident detection means, and outputs the trip command on condition that the external accident detection signal is not input when the internal accident detection signal is input. It is obtained by constituting the line protection relay device according to claim that a lip command means.

As a seventh device, a section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source and a branch point and a middle of a branch line among lines of a branch line branched from this power transmission line. In a line protection relay device in which a section of a line connecting to the circuit breaker is a protection target section, a pair of current detection means for detecting currents at both ends of the power transmission line, and detected currents of the respective current detection means are main data. A current deviation calculating means for taking in via a transmission line and calculating a deviation between the two; an internal accident detection signal outputting means for outputting an internal accident detection signal when the calculated value of the current deviation calculating means exceeds a set value; Auxiliary current detection means for detecting the current on the terminal side of the line, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, and the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means. External accident detection signal output means for outputting an external accident detection signal when it is detected from the detection output of the above that an accident has occurred outside the protection target section, and an external accident detection while receiving the output signal of the internal accident detection signal output means. A trip command means for receiving a signal output from the signal output means through the auxiliary data transmission line and outputting a trip command on condition that the external accident detection signal is not input when the internal accident detection signal is input. This is a configuration of a line protection relay device.

[0016]

According to the above means, the state of the electric signal of the power transmission line is monitored, and when the state change corresponding to the accident in the protection target section occurs, the internal accident detection signal is output. On the other hand, the state of the electric signal of the branch line is monitored, and when a state change corresponding to an accident outside the protection target section is detected, an external accident detection signal is output. When the internal accident detection signal is output, the circuit breaker in the power transmission line is tripped on the condition that the external accident detection signal is not output, assuming that an internal accident has occurred in the protection target section. That is, when the internal accident detection signal is output and the external accident is not detected by the external accident detection means, a process of tripping the circuit breaker in the power transmission line is performed because an accident has occurred in the protection target section.

On the other hand, when the auxiliary internal accident detection means for monitoring the condition of the electric signal of the branch line and outputting the internal accident detection signal when the state change corresponding to the accident in the protection target section is detected is provided. The circuit breaker in the power transmission line is tripped on condition that the main internal accident detection signal is output from the main internal accident detection means and the auxiliary internal accident detection means. This makes it possible to detect an accident in the protected area with high sensitivity and protect the line.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram when a line protection relay device is installed in a power transmission system. In FIG. 1, the power source E
Electrical stations 1, 2, 3, and 4 are provided in a power transmission system including 1, E2. Power station 1 is connected to power source E1 and power station 2
Is connected to the power source E2, and each of the electric stations 1 and 2 is a circuit breaker 41,
42 and the power transmission line 11 are connected. Power transmission line 11
A branch line 1 branched from this transmission line 11 in the middle of the line
2 and 13 are connected. Electrical stations 3 and 4 are provided on the terminal sides of the respective branch lines 12 and 13. The electric station 3 is connected to the branch line 12 via a circuit breaker 43, and is connected to a load L3 via a transformer T3. The electric station 4 is connected to the branch line 13 via a circuit breaker 44, and is connected to a load L4 via a transformer T4. A line including the power transmission line 11 connecting the circuit breaker 41 and the circuit breaker 42 and the branch lines 12 and 13 is set as a protection target section of the line protection relay device. In order to detect an accident in the protected section with high sensitivity, the electric station 1 is provided with a current transformer 21, a voltage transformer 31, and a main relay 100, and the electric station 2 is provided with a current transformer 22, a voltage transformer. Vessel 32,
The main relay 200 is provided, and the current transformer 23,
A voltage transformer 33 and a directional relay 300 are provided, and a transformer 24, a voltage transformer 34, and a directional relay 400 are provided in the electric station 4.
Is provided. The main relay 100 and the main relay 200 are a high-speed data transmission line 110 and a low-speed data transmission line 120.
Are connected through the relays 300 and 400 in each direction.
Via the low speed data transmission line 120, the main relay 100,
It is connected to 200.

The current transformers 21 and 22 are configured as current detecting means for detecting the current of the transmission line 11, and the voltage transformers 31 and
Reference numeral 32 is configured as voltage detection means for detecting the voltage of the power transmission line 11. The current transformers 23 and 24 are the branch lines 12 and 1, respectively.
3 is configured as an auxiliary current detection unit that detects the current of 3,
The voltage transformers 33 and 34 are configured as auxiliary voltage detecting means for detecting the voltage of each branch line 12 and 13. The current transformers 21, 22, 23, 24 have the same phase as the currents I1, I2, I3, I4 of the respective lines flowing into the fault point F1 when an internal fault occurs at the fault point F1 of the power transmission line 11. At this time, the polarities are matched so that the outputs of the current transformers 21, 22, 23 and 24 have the same phase. Further, the polarities of the voltage transformers 31, 32, 33, 34 are also matched in the same manner as the current transformers.

The directional relays 300 and 400 are configured as external accident detecting means for detecting an accident outside the protection target section, and the detection sensitivity is set to a level at which it is not judged to be an external accident during normal maximum load operation. ing. Specifically, as shown in FIG. 2, the directional relay 300 is
It is configured by including short-circuit direction distance relays 301, 302, 303, a ground fault direction relay 304, and an AND gate 305. Since the directional relay 300 and the directional relay 400 are the same, only the directional relay 300 will be described.

Short-circuit direction distance relays 301, 302, 30
3 is for the AB phase in the three-phase AC of the A, B and C phases, BC
It is configured as a phase and CA phase relay, and outputs a signal of "0" when an accident occurs on the load L3 side from the detected current I3 of the current transformer 23 and the detected voltage V3 of the voltage transformer 33. However, at other times, a signal of "1" is output. These relays are designed to judge whether or not an accident has occurred outside the protected section based on the phases of voltage and current. Instead of these relays, it is also possible to use a relay with a mower characteristic.

On the other hand, the ground fault direction relay 304 comprises a detector for detecting a zero-phase voltage and a zero-phase current, for example, and outputs a signal of "0" when an accident occurs outside the protected area. It outputs the signal, and outputs a signal of "1" at other times. And each relay 301-304
Is output to the AND gate 305. AND
The gate 305 outputs a trip allowable output signal of "1" when a signal of "1" is input from each of the relays 301 to 304 on the assumption that an accident has not occurred outside the protected area. There is. That is, this trip permission output signal is output as an internal accident detection signal. Further, the AND gate 305 outputs the signal of "0" as the external accident detection signal when the signal of "0" is output from any of the relays, because the accident occurs outside the protection target section. . Therefore, the directional relay 300 constitutes an internal accident detecting means when the accident determination is performed using "1" of the signal output from the AND gate 305, and an external accident detecting means when the "0" is used. Will be done. In addition, ground fault direction relay 3
04, in order to prevent erroneous determination in a short circuit accident,
It is also possible to use the one with the short-circuit accident detection priority and not outputting the trip allowable output signal in the case of a short-circuit accident.

On the other hand, the main relays 100 and 200 are composed of the same one, and the detection currents detected by the current transformers 21 and 22 are converted into digital signals by synchronous sampling, and these digital signals are transmitted at high speed data transmission lines. They are mutually transmitted via 110. Further, signals from the directional relays 300 and 400 are input to the main relays 100 and 200 via the low speed data transmission line 120. The low-speed data transmission line 120 can use a telephone line because it only transmits signals of "1" and "0".

As shown in FIG. 3, the main relay 100 comprises a digital converter 101, a transmission device 102, a delay circuit 104, a current differential determination section 104, a voltage relay 105, a transmission device 106, and an AND gate 107. It is configured. The digital converter 101 samples the current detected by the current transformer 21 in synchronization with the main relay 200, converts the sampled signal into a digital signal, and outputs the digital signal to the transmission device 102 and the delay circuit 103. It has become. The transmission device 102 is the digital converter 1
The digital signal from 01 is transmitted to the main relay 200 via the high-speed data transmission line 110, and the digital signal from the main relay 200 is output to the current differential determination unit 104. The delay circuit 103 is the digital converter 10
The current signal sampled at the same time of the current information obtained by sampling the detection current of the current transformer 21 and the current information obtained by sampling the detection current of the current transformer 22 is the current differential signal after delaying the digital signal from 1 for a certain time. It is configured to compensate for the transmission delay time so that it can be input to the determination unit 104. When the deviation between the detected current of the current transformer 21 and the detected current of the current transformer 22 exceeds a set value, the current differential determination unit 104 determines that an internal accident has occurred in the protection target section,
The trip allowable output signal of "1" is output. That is, the current differential determination unit 104 constitutes not only the current deviation calculation means but also the main internal accident detection signal output means.

The voltage relay 105 comprises a line voltage shortage detector and a zero-phase overvoltage detector, and when the line voltage drops due to a short-circuit accident in the protected section, the line voltage shortage occurs. The detector outputs a signal of "1", and when a ground fault occurs in the protection target section, the zero-phase overvoltage detector outputs a signal of "1". The output signal of the voltage relay 105 is input to the AND gate 105. The AND gate 107 is connected to the transmission device 10
6. Directional relay 30 via low speed data transmission line 120
A signal from 0,400 is input.
The AND gate 107 receives the trip allowance signal of “1” from the direction relay 300 and the trip allowance output signal of “1” from the current differential determination unit 104,
Further, when the trip permission output signal of "1" is input from the voltage relay 105, it is configured as trip command means for outputting a cutoff command signal. AND gate 10
When the disconnection command signal is output from 7, the trip coil of the circuit breaker 41 is excited and the circuit breaker 41 is tripped. That is, the AND gate 107 constitutes the circuit breaker trip means together with the trip coil.

In the above structure, when no accident occurs outside the protected section, the directional relays 300 and 400 output the trip allowable output signal of "1". This signal is sent to the main relay 1 via the low speed data transmission line 120.
00,200. At this time, the states of the electric signals of the power transmission line 11 are the current transformers 21 and 22 and the voltage transformers 31 and 3.
When the combined value of the detected currents I1 and I2 does not exceed the set value, the current differential determination unit 1
Since the signal "0" is output from 04, the disconnection command signal is not output from the AND gate 107, and the circuit breaker 4
Both 1, 42 are kept closed. When an internal accident occurs at the accident point F1 during power transmission in such a state, the combined value of the detected currents I1 and I2 exceeds the set value, and the current differential determination unit 104 allows the trip of "1". The output signal is output and the voltage relay 105 outputs a trip permission output signal. This allows AN
The condition of the logical product of the D gate 107 is satisfied, and the disconnection command signal is output from the AND gate 107 to cause the circuit breakers 41, 4
2 will be tripped.

On the other hand, when an accident does not occur in the protection target section and an accident occurs outside the protection target section, for example, an external accident occurs in the line connecting the transformer T3 and the load L3 of the electric station 3. When a short circuit occurs, the short-circuit direction distance relay 30
One of the relays 1 to 303 operates, the output of the relay becomes "0", and the output of the AND gate 305 is inverted from "1" to "0". This signal is input to the AND gate 107 via the low-speed data transmission line 120 and the transmission device 106. Therefore, even if the combined value of the detected currents I1 and I2 exceeds the set value and the trip allowable output signal is output from the current differential determination unit 104 due to an accident outside the protection target section, the logical product condition of the AND gate 107 The condition is not satisfied, and the shutoff command signal is not output from the AND gate 107.

As described above, according to this embodiment, the directional relays 300 and 400 detect whether or not an accident has occurred outside the protected section, and the detected signal is used as the low speed data transmission line 12.
0 to the main relays 100 and 200, and whether an accident occurs in the protection target section based on the state of the electric signal of the power transmission line 11 and the signals from the direction relays 300 and 400 in each of the main relays 100 and 200. Since it is determined whether or not there is an accident, it is possible to detect an accident in the protected area with high sensitivity.

Further, in the above embodiment, the main relay 10
Although the one using the voltage relay 105 as the component of 0,200 has been described, without using the voltage relay 105,
It is also possible to output the cutoff command signal according to the signals from the current differential determination unit 104 and the direction relays 300 and 400.

[0031]

As described above, according to the present invention,
From the state of the electric signal of the transmission line, it is determined whether or not an accident has occurred in the protected section, and from the state of the electric signal of the branch line, it is determined whether or not an accident has occurred in the protected section. Since it is determined whether or not an accident has occurred in the protection target section from the judgment result of 1., the accident in the protection target section can be detected with high sensitivity.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a line protection relay device showing an embodiment of the present invention.

FIG. 2 is a specific configuration diagram of a directional relay.

FIG. 3 is a specific configuration diagram of a main relay.

[Explanation of symbols]

 1, 2, 3, 4 Electric power station 11 Transmission line 12, 13 Branch line 21, 22, 23, 24 Current transformer 31, 32, 33, 34 Voltage transformer 41, 42, 43, 44 Circuit breaker 100, 200 Main Relay 300, 400 directional relay

Claims (7)

[Claims] 1. A section of a line connecting a circuit breaker and a circuit breaker among lines of a transmission line connected to a power source, and a branch point of a line of a branch line branched from this power line and a circuit breaker in the branch line. In a line protection relay device in which a section of a line connecting the lines is a protection target section, an internal accident detection signal is acquired when a state change corresponding to an accident in the protection target section is detected from the electric signal of the power transmission line. An internal accident detection means for outputting
An external accident detection means that takes in an electric signal of the branch line and outputs an external accident detection signal when a state change corresponding to an accident outside the protection target section is detected from this electric signal,
A circuit breaker trip means for receiving the output of the internal accident detection means and the output of the external accident detection means and tripping the circuit breaker in the power transmission line on condition that the external accident detection signal is not input when the internal accident detection signal is input. A line protection relay device characterized in that 2. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, a branch point of a line of a branch line branched from this power transmission line, and a circuit breaker in the branch line. In a line protection relay device in which a section of a line connecting the lines is a protection target section, an internal accident detection signal is acquired when a state change corresponding to an accident in the protection target section is detected from the electric signal of the power transmission line. And a main internal accident detection means for outputting an electric signal of the branch line and an auxiliary internal accident detection for outputting an internal accident detection signal when a state change corresponding to an accident in the protection target section is detected from the electric signal. Means, and the outputs of the main internal accident detection means and the auxiliary internal accident detection means are received, and the circuit breaker in the transmission line is tripped on condition that an internal accident detection signal is input from each internal accident detection means. Line protection relay apparatus characterized by comprising a circuit breaker trip unit for up. 3. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, a branch point of a line of a branch line branched from this power line, and a circuit breaker in the branch line. In a line protection relay device in which a section of a line connecting the lines is a protection target section, a pair of current detection units that detect currents at both ends of the power transmission line, and a current deviation that calculates a deviation of a detection current of each current detection unit. Calculation means, internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and auxiliary current detection means for detecting the current on the terminal side of the branch line. , An auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, and the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means are taken in, and an accident occurs outside the protection target section from these detection outputs. That When an external accident detection signal is output, an external accident detection signal output means, an internal accident detection signal output means output signal, and an external accident detection signal output means output signal are received, and an external accident detection signal is input when the internal accident detection signal is input. And a circuit breaker trip means for tripping the circuit breaker in the transmission line on the condition that there is no input. 4. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, and a branch point and a circuit breaker in the branch line of a line of a branch line branched from this power transmission line. In a line protection relay device in which a section of a line connecting the lines is a protection target section, a pair of current detection units that detect currents at both ends of the power transmission line, and a current deviation that calculates a deviation of a detection current of each current detection unit. Calculation means, main internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and auxiliary current detection means for detecting the current on the terminal side of the branch line. An auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, and the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means are taken in, and an accident occurs in the protection target section from these detection outputs. Was it Auxiliary internal accident detection signal output means for outputting an internal accident detection signal when detected, and each internal accident detection signal output means for receiving the output signals of the main internal accident detection signal output means and the auxiliary internal accident detection signal output means And a circuit breaker trip means for tripping a circuit breaker in the power transmission line on condition that an internal accident detection signal is input from the line protection relay device. 5. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, and a branch point of a line of a branch line branched from this power line and a circuit breaker in the branch line. In a line protection relay device in which a section of a line connecting the lines is a section to be protected, a pair of current detection means for detecting currents at both ends of the power transmission line, and a detection current of each current detection means via a main data transmission line. Current deviation calculation means for calculating the deviation between the two, an internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and the terminal side of the branch line. Auxiliary current detection means for detecting the current of the branch line, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means, and from these detection outputs An external accident detection signal output means for outputting an external accident detection signal when an accident is detected outside the protected section, and an external accident detection signal output means for receiving an output signal from the internal accident detection signal output means. And a circuit breaker trip means for tripping the circuit breaker in the power transmission line on condition that the external accident detection signal is not input when the internal accident detection signal is input when the output signal is received via the auxiliary data transmission line. Characteristic track protection relay device. 6. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, a branch point of a line of a branch line branched from this power line, and a circuit breaker in the branch line. In a line protection relay device in which a section of a line connecting the lines is a protection target section, an internal accident detection signal is acquired when a state change corresponding to an accident in the protection target section is detected from the electric signal of the power transmission line. An internal accident detection means for outputting
An external accident detection means that takes in an electric signal of the branch line and outputs an external accident detection signal when a state change corresponding to an accident outside the protection target section is detected from this electric signal,
It is characterized by comprising trip command means for receiving the output of the internal accident detection means and the output of the external accident detection means and outputting a trip command on condition that the external accident detection signal is not input when the internal accident detection signal is input. Track protection relay device. 7. A section of a line connecting a circuit breaker and a circuit breaker among lines of a power transmission line connected to a power source, and a branch point and a circuit breaker in the branch line of a line of a branch line branched from this power transmission line. In a line protection relay device in which a section of a line connecting the lines is a section to be protected, a pair of current detection means for detecting currents at both ends of the power transmission line, and a detection current of each current detection means via a main data transmission line. Current deviation calculation means for calculating the deviation between the two, an internal accident detection signal output means for outputting an internal accident detection signal when the calculated value of the current deviation calculation means exceeds a set value, and the terminal side of the branch line. Auxiliary current detection means for detecting the current of the branch line, auxiliary voltage detection means for detecting the voltage on the terminal side of the branch line, the detection output of the auxiliary current detection means and the detection output of the auxiliary voltage detection means, and from these detection outputs An external accident detection signal output means for outputting an external accident detection signal when an accident is detected outside the protected section, and an external accident detection signal output means for receiving an output signal from the internal accident detection signal output means. A line protection relay characterized by comprising trip command means for receiving an output signal via an auxiliary data transmission line and outputting a trip command on condition that no external accident detection signal is input when an internal accident detection signal is input. apparatus.