JP2002044861A - Protection device of branch reactor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety and reliable protection device of a branch reactor system to prevent a failure of breaking of a circuit breaker for a transmission line completely and an accident of line-to-ground fault when a detecting means of the accident malfunctions. SOLUTION: The first current detecting circuit 3 detects that currents flowing in switches for a branch reactor 16a, 16b are less than breaking currents of the switches 16a, 16b. An output circuit of an instruction to trip 17 outputs the instruction to the switches 16a, 16b according to a signal of detected accident from a circuit for detecting the accident in the branch reactor 1. When outputs from the circuit 1 and the circuit 3 meet a condition of logical product, an AND circuit 4 enables the instruction from the circuit 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection device for a shunt reactor system having a transmission line circuit breaker for interrupting a transmission line and a shunt reactor collectively.
The present invention relates to a protection device for a shunt reactor system that prevents an interruption of a circuit breaker for a transmission line due to a malfunction when a voltage is applied to a shunt reactor.

[0002]

2. Description of the Related Art In general, in an ultra-high voltage system or a 500,000 volt system, a shunt reactor system in which a shunt reactor for compensating the charging current is connected to a transmission line is employed. FIG. 5 is a configuration diagram of the shunt reactor system. As shown in this figure, shunt reactor switches 16a and 16b are connected to both ends of a transmission line 13 such as a power cable, and the shunt reactors are connected via the shunt reactor switches 16a and 16ba. 15 a and 15 b are connected in parallel to the transmission line 13. Further, at both ends of the transmission line 13, there are disposed transmission line breakers 12a and 12b for simultaneously cutting off the transmission line 13 and the shunt reactors 15a and 15b. Note that reference numeral 14 denotes a capacitance of the transmission line 13 to the ground. Although FIG. 5 shows an example in which the shunt reactors 15a and 15b are installed at both ends of the transmission line 13, they may be installed only at one end.

The above shunt reactor system incorporates a protection device for protecting the system in the event of an accident. The protection device of the shunt reactor system usually includes an accident detection circuit for detecting an accident in the shunt reactors 15a and 15b or the transmission line 13, and an output of the circuit breaker 12 for the transmission line.
a and a trip command output circuit for outputting a trip command to 12b. Such a protection device is provided by shunt reactors 15a and 15b depending on an object to be detected.
6 and the latter is shown in FIG.
The configuration is as shown in FIG.

That is, the shunt reactors 15a and 15b
Of the shunt reactors 15a, 15
b is provided with a shunt reactor fault detection circuit 1 for detecting a fault inside and outputting a fault detection signal. The fault detection circuit 1 trips to circuit breakers 12a and 12b for transmission lines based on the fault detection signal. A trip command output circuit 2 for outputting a command is connected (FIG. 6). On the other hand, as a configuration for protecting the transmission line 13, there is provided a transmission line accident detection circuit 5 that detects an accident of the transmission line 13 and outputs an accident detection signal. A trip command output circuit 6 for outputting a trip command to the electric circuit breakers 12a and 12b is connected (FIG. 7).

In the above shunt reactor system protection device, when the accident detection circuits 1 and 5 operate, the trip command output circuits 2 and 6 output a trip command to the transmission line breakers 12a and 12b, and The circuit breakers 12a and 12b are tripped, thereby realizing protection of the shunt reactors 15a and 15b or the transmission line 13. That is, in the conventional protection device of the shunt reactor system, the transmission line circuit breakers 12a and 12b are shut off regardless of the accident of the shunt reactors 15a and 15b or the accident of the transmission line 13. For this reason, the shunt reactor switches 16a, 16b
Does not need to have an accident blocking performance and can be inexpensive.

Incidentally, the shunt reactors 15a and 15b
, A rush current IL flows. Further, the transmission line 13 has a ground capacitance 14, and the charging current Ic flows. FIG. 8 shows the state at that time by taking a case where a voltage is applied to the shunt reactor 15b as an example.

[0007] The inrush current IL includes an AC component and a DC component as shown in (b), but the AC component flows with a phase of 90 degrees with a delay, and the charging of the transmission line 13 with a lead of 90 degrees shown in (a). The phase is opposite to the current Ic. Further, the shunt reactors 15a, 1
Since the capacity of 5b is generally selected so as to substantially cancel the charging current Ic of the transmission line 13, the zero point transition current (Ic + IL) flowing through the transmission line breaker 12a is (c).
As shown in (2), the AC component is greatly reduced, and the DC component that is not reduced remains as it is. Therefore, the zero-point transition current in (c) is a current in a state having no current zero point. This phenomenon of having no current zero point is called a current zero miss phenomenon.

[0008]

As described above, when a voltage is applied to the shunt reactors 15a and 15b, if the shunt reactors 15a and 15b are normal, the current flowing through the circuit breakers 12a and 12b for transmission lines is used. Becomes a zero point transition current, and a current zero miss phenomenon occurs. At this time, the protection device of the shunt reactor system malfunctions and the transmission line breaker 12
When the trip command is output to the transmission line breakers 12a and 12b, the transmission line breakers 12a and 12b cut off the current having no current zero point because of the DC component current.

However, the breaking performance of the transmission line breakers 12a and 12b, which are AC circuit breakers, is significantly reduced unless there is a zero current point. Therefore, the circuit breakers 12a, 12b
Could not be shut down and could lead to a ground fault. Although the number of malfunctions of the shunt reactor system protection device is small, it is not completely possible. Possible causes of the malfunction include an increase in an error current due to saturation of a current transformer (not shown) for detecting a supply current to the fault detection circuit, generation of a surge current, and the like.

[0010] The shunt reactor system is employed in important systems such as an ultra-high voltage system and a 500,000 volt system, and the economic loss in the event of an accident becomes enormous. For this reason, even if the malfunction of the protection device is rare, the failure of the transmission line circuit breaker to be guided thereby may cause a serious situation. However, at present, only measures are taken to prevent the malfunction of the shunt reactor or the protection device of the transmission line as much as possible, and it has been difficult to completely prevent the uninterruptibility of the circuit breaker for the transmission line.

The present invention has been proposed in order to eliminate the inability of the circuit breaker for transmission lines to be interrupted due to the above-mentioned zero current error phenomenon. The main object of the present invention is to provide a protection device for a shunt reactor system that can completely prevent the occurrence of ground faults and prevent the occurrence of a ground fault, and is excellent in safety and reliability.
Another object of the present invention is to provide a protection device for a shunt reactor system that can reliably shut off a circuit breaker for a transmission line when an accident occurs and a large accident current flows. .

[0012]

In order to achieve the above object, the present invention provides a shunt reactor for compensating a charging current of a transmission line, and a shunt for connecting the shunt reactor to the transmission line in parallel. A protection device used in a shunt reactor system including a reactor switch and a transmission line circuit breaker that collectively shuts off the transmission line and the shunt reactor has the following features. .

According to the first aspect of the present invention, there is provided a shunt reactor accident detecting means for detecting an internal accident in the shunt reactor and outputting an accident detection signal, and the shunt reactor switch based on the accident detection signal. Trip command output means for outputting a trip command, and first current detection means for detecting that a current flowing through the shunt reactor switch is equal to or less than a current value that can be cut off by the shunt reactor switch. A trip command output from the trip command output means when the logical product condition of the shunt reactor accident detection means and the first current detection means is satisfied. I have.

In the first aspect of the present invention, when a voltage is applied to the shunt reactor and an inrush current flows, the shunt reactor fault detection means malfunctions and outputs a fault detection signal. The trip command output means outputs a trip command to the switch for shunt reactor based on. Since the inrush current of the shunt reactor is equal to or less than the current value that can be cut off by the shunt reactor switch, the first current detecting means detects the current flowing through the shunt reactor switch (here, the inrush current of the shunt reactor). ) Is detected to be equal to or less than the current value that can be cut off by the shunt reactor switch.

That is, after the shunt reactor fault detecting means has been operated, the first current detecting means has performed a detecting operation. This means that the shunt reactor fault detecting means and the first
Means that the logical product condition of the current detecting means is satisfied. Only when this condition is satisfied, the trip command output from the trip command output means to the shunt reactor switch becomes valid, and the shunt reactor switch is tripped.

The current interrupted by the shunt reactor switch is a current obtained by superimposing an AC component and a DC component, but the AC component is not reduced at all. That is, the current zero miss phenomenon does not occur in the shunt reactor portion, and the shunt reactor has a current zero point. In addition, the rush current of the shunt reactor due to the voltage application is less than the breaking performance of the shunt reactor switch, so interrupting this current is within the breaking capability of the shunt reactor switch. Without any problems
Reliable shutoff is possible.

According to the first aspect of the present invention, when a voltage is applied to the shunt reactor, even if the shunt reactor fault detection means malfunctions, the current value flowing through the shunt reactor switch is reduced. If the current value of the shunt reactor switch is equal to or less than the interruptable current value, the shunt reactor switch is cut off, not the transmission line breaker in which the zero current error phenomenon occurs. Therefore, there is no possibility that the circuit breaker for the transmission line will not be cut off, and there is no fear that a ground fault will occur.

When the shunt reactor accident detecting means operates normally and detects an internal accident of the shunt reactor,
The trip command output means outputs a trip command to the shunt reactor switch according to the output of the accident detection signal. The current generated by the accident flows through the shunt reactor switch. If the first current detecting means determines that the accident current value is equal to or less than the current value that can be shut off by the shunt reactor switch, The logical product condition of the reactor accident detection means and the first current detection means is satisfied, and the trip command from the trip command output means becomes valid. As a result, the shunt reactor switch can reliably cut off a small fault current that is equal to or less than the cutoff current value.

According to a second aspect of the present invention, a transmission line fault detection means for detecting a fault in the transmission line and outputting a fault detection signal, and a trip command to the shunt reactor switch based on the fault detection signal. Trip command output means for outputting, and first current detection means for detecting that the current flowing through the shunt reactor switch is equal to or less than a current value that can be cut off by the shunt reactor switch, A trip command output from the trip command output means is validated when a logical product condition of the transmission line fault detection means and the first current detection means is satisfied.

The second aspect of the present invention shows a countermeasure for the case where the transmission line fault detecting means malfunctions, not the malfunction of the shunt reactor fault detecting means according to the first aspect of the present invention. That is, when a voltage is applied to the shunt reactor and an inrush current flows, the transmission line fault detection means malfunctions and outputs a fault detection signal, and based on the fault detection signal, the trip command output means sets the shunt reactor. Outputs a trip command to the switch. As described above, the rush current of the shunt reactor is equal to or less than the current value that can be cut off by the shunt reactor switch.
The logical product condition of the current detection means is satisfied, the trip command from the trip command output means becomes valid, and the shunt reactor switch is tripped.

According to the second aspect of the present invention, when a voltage is applied to the shunt reactor, even if the transmission line fault detection means malfunctions, the value of the current flowing through the shunt reactor switch does not change. If the current value is below the
Since this current has a current zero point, the shunt reactor switch can reliably shut off the current. Therefore,
It is possible to avoid a breaking operation in a power line breaker through which a current having no current zero point flows. Thus, it is possible to prevent the transmission line breaker from being unable to shut off, and to prevent the occurrence of a ground fault accident.

When the transmission line fault detection means operates normally and detects a fault in the transmission line, the trip command output means outputs a trip command to the shunt reactor switch according to the output of the fault detection signal. . The current generated by the accident flows through the shunt reactor switch. If the first current detecting means determines that the fault current value is equal to or less than the current value that can be cut off by the shunt reactor switch, the transmission line The logical product condition of the accident detection means and the first current detection means is satisfied, and the trip command from the trip command output means becomes valid. As a result, the shunt reactor switch can reliably shut off a small fault current that is equal to or less than the cutoff current value.

According to a third aspect of the present invention, there is provided a shunt reactor fault detecting means for detecting a fault inside the shunt reactor and outputting a fault detection signal, and tripping to the transmission line breaker based on the fault detection signal. A trip command output means for outputting a command; and a second current detection means for detecting that a current flowing through the shunt reactor switch exceeds a current value that can be cut off by the shunt reactor switch. ,
The trip command output from the trip command output means is validated when a logical product condition of the shunt reactor accident detection means and the second current detection means is satisfied.

According to the third aspect of the present invention, when a voltage is applied to the shunt reactor and there is an accident inside the shunt reactor, the shunt reactor accident detection means detects this and outputs an accident detection signal. . The trip command output means outputs a trip command to the transmission line breaker based on the accident detection signal. The fault current generated due to an internal fault in the shunt reactor flows through the shunt reactor switch. If the fault current exceeds a current value that can be cut off by the shunt reactor switch, the second current detection means detects the fault current. Perform the operation. That is, the logical product condition of the shunt reactor accident detecting means and the second current detecting means is satisfied. For this reason, the trip command output from the trip command output means to the transmission line breaker becomes valid, and the transmission line breaker is tripped.

According to the third aspect of the present invention, when a voltage is applied to the shunt reactor and the shunt reactor fault detecting means operates, the current flowing through the shunt reactor switch changes the current flowing through the shunt reactor switch. If the second current detecting means detects that the current value exceeds the cutoff current of the switch, not the switch for the shunt reactor but the circuit breaker for the transmission line is cut off. If the interrupting current is large enough to exceed the interruptable current value of the shunt reactor switch, an internal accident has definitely occurred in the shunt reactor, and the operation of the shunt reactor accident detection means is normal. It can be determined that there is. In other words, an accident has actually occurred inside the shunt reactor, and this means that the current zero failure phenomenon has not occurred in the circuit breaker for the transmission line. Therefore, the current interrupted by the circuit breaker for transmission lines has a current zero point, and the circuit breaker for transmission lines can reliably shut off the fault current while maintaining excellent breaking performance.

According to a fourth aspect of the present invention, there is provided a transmission line fault detecting means for detecting a fault in the transmission line for each phase and outputting a fault detection signal, and transmitting the fault to the transmission line breaker based on the fault detection signal. Trip command output means for outputting a trip command, and second current detection means for detecting that a current flowing through the shunt reactor switch exceeds a current value that can be shut off by the shunt reactor switch are provided. The trip command output by the trip command output means is validated when a logical product condition of the transmission line fault detection means and the second current detection means is satisfied.

The above-mentioned invention of claim 4 shows a countermeasure when the transmission line fault detecting means operates. That is, when the transmission line fault detection means operates and outputs a fault detection signal, the trip command output means outputs a trip command to the transmission line breaker based on the fault detection signal. The fault current generated by the fault in the transmission line flows through the shunt reactor switch. If the fault current exceeds a current value that can be cut off by the shunt reactor switch, the second current detection means performs the detection operation. Do. That is, the logical product condition of the transmission line fault detection means and the second current detection means is satisfied, and the trip command output from the trip command output means to the transmission circuit breaker becomes effective, and Trip the vessel.

According to the fourth aspect of the present invention, when a voltage is applied to the shunt reactor and the transmission line fault detection means operates, the current flowing through the shunt reactor switch changes the current flowing through the shunt reactor switch. If the current value that can be cut off is exceeded,
Cut off the circuit breaker for the transmission line, not the switch for the shunt reactor. If the interrupting current is large enough to exceed the interruptable current value of the shunt reactor switch, the occurrence of an accident in the transmission line is certain, and it can be determined that the transmission line accident detection means is normal. At this time, no zero current phenomenon has occurred in the circuit breaker for transmission lines. Therefore, the circuit breaker for transmission lines can reliably cut off the current having the zero current point. In addition, since there is a possibility that the zero current phenomenon has occurred in the phases other than the fault phase, the power line fault detecting means detects a fault in the power line for each phase.

According to a fifth aspect of the present invention, in the protective device for a shunt reactor system according to the third or fourth aspect, the power line breakers are arranged at both ends of the power line, and the output of the trip command output means is provided. Transfer trip command output means for transferring the trip command to the transmission line breaker disposed at the opposite end of the transmission line breaker to which the trip command has been output when the trip command is enabled. It is characterized by the following.

In the fifth aspect of the present invention, the fact that the trip command output to the transmission line breaker by the trip command output means is effective means that the shunt reactor fault detection means or the transmission line fault detection means detects the fault. That is, the second current detection means has determined that the current caused by the accident is large enough to exceed the current value that can be cut off by the shunt reactor switch. At this time, since the transfer trip command output means transfers the trip command to the transmission line breaker arranged at the opposite end of the transmission line breaker, the transmission line breakers at both ends of the transmission line are quickly tripped. be able to. This makes it possible to further enhance the safety and reliability of the shunt reactor system.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment: Corresponding to Claim 1 [Configuration] An example of an embodiment of the present invention will be specifically described below with reference to the drawings. The first embodiment corresponds to claim 1, and FIG. 1 is a block diagram of the first embodiment. In FIG. 1, the same parts as those in the conventional example shown in FIG. The configuration of the shunt reactor system is the same as that of the conventional example shown in FIG.

In the first embodiment, the shunt reactor fault detection circuit 1, the first current detection circuit 3, the trip command output circuit 17, the first current detection circuit 3, and the trip command output circuit 17 Are connected to an AND circuit 4. The first current detection circuit 3 is configured to detect that the current flowing through the shunt reactor switches 16a and 16b is equal to or less than a current value that can be cut off by the shunt reactor switches 16a and 16b. I have. The trip command output circuit 17 outputs a shunt reactor switch 16 based on an accident detection signal from the shunt reactor accident detection circuit 1.
a, and 16b are output. The AND circuit 4 is configured to validate the trip command from the trip command output circuit 17 when a logical product condition of the shunt reactor accident detection circuit 1 and the first current detection circuit 3 is satisfied.

[Operation] Next, the operation of the first embodiment having the above configuration will be described with reference to an example in which a voltage is applied to the shunt reactor 15b. That is, when a voltage is applied to the shunt reactor 15b, an inrush current flows. Shunt reactor accident detection circuit 1 is shunt reactor 1
If there is no accident in 5b, it will not operate if it is normal, but may malfunction for some reason. As described above, the cause of the malfunction may be an increase in the error current or the occurrence of a surge current due to the saturation of the current transformer detecting the current supplied to the fault detection circuit 1. In any case, the current flowing through the shunt reactor 15b is a current value that does not cause any problem in the breaking performance of the shunt reactor switch 16b, and the first current detection circuit 3 detects this.

When a fault detection signal is output due to a malfunction of the shunt reactor fault detection circuit 1, the trip command output circuit 17 outputs a trip command to the shunt reactor switch 16b based on the fault detection signal. The AND circuit 4 confirms that these conditions, that is, that the logical product conditions of the shunt reactor fault detection circuit 1 and the first current detection circuit 3 are met.
Is determined, the trip command output from the trip command output circuit 17 to the shunt reactor switch 16b is valid, and the shunt reactor switch 16b is tripped.

As described above, the first embodiment is different from the conventional protection device in that not the transmission line breakers 12a and 12b but the shunt reactor switches 16a and 16b are tripped. . At this time, the current interrupted by the shunt reactor switch 16b is a superimposed current of the AC component and the DC component, but the shunt reactor 15b has no current zero miss phenomenon and has a current zero point. The shunt reactor switch 16b is not more than the breaking performance of the shunt reactor switch 16b. The above is a shunt reactor 15b
Has been described, but when a voltage is applied to the shunt reactor 15a or the cable 13
The same applies when a voltage is simultaneously applied to the shunt reactors 15a and 15b.

[Effect] As described above, according to the first embodiment, even if the shunt reactor fault detection circuit 1 malfunctions due to the shunt reactor rush current at the time of voltage application, the first
The current detected by the current detection circuit 3 is determined to be within the breaking capability of the shunt reactor switches 16a and 16b, and the trip command from the trip command output circuit 17 is validated.
The shunt reactor switches 16a and 16b can be tripped.

As shown in FIG. 6B, the shunt reactors 15a and 15b are superimposed with the AC and DC components of the rush current, and the AC components are not reduced at all. There is a zero current point. In addition, the inrush current of the shunt reactors 15a and 15b due to the voltage application is lower than the breaking performance of the shunt reactor switches 16a and 16b, so that there is no problem in opening the shunt reactor switches 16a and 16b without any problem. Can be cut off. As a result, the transmission line breakers 12a and 12b do not cut off the current having no current zero point, so that the interruption is not impossible and the development to the ground fault can be prevented.

As another case, the shunt reactor accident detection circuit 1 operates normally and the shunt reactor 15
a and 15b may be detected. When an accident detection signal is output by the operation of the shunt reactor accident detection circuit 5, the trip command output circuit 17 outputs a trip command to the shunt reactor switches 16a and 16b based on the accident detection signal. At this time, if the first current detection circuit 3 determines that the current generated by the accident is equal to or less than the current value at which the shunt reactor switches 16a and 16b can be cut off, the trip command from the trip command output circuit 17 is output. Becomes effective, and the shunt reactor switch 16a,
16b is tripped, and the shunt reactor switch 16
a and 16b can interrupt a small fault current that is not more than a current value that can be interrupted without any problem.

(2) Second Embodiment Corresponding to Claim 2 [Structure] Next, a second embodiment corresponding to claim 2 will be specifically described with reference to the block diagram of FIG. I do. In FIG. 2, the same parts as those in the conventional example shown in FIG. 7 and the first embodiment shown in FIG. The configuration of the shunt reactor system is the same as that of the conventional example shown in FIG.

In the second embodiment, the transmission line fault detection circuit 5, the first current detection circuit 3, the trip command output circuit 18, and the first current detection circuit 3 and the trip command output circuit 18 And an AND circuit 7 connected thereto. The trip command output circuit 18 outputs a trip command to the shunt reactor switches 16a and 16b based on an accident detection signal from the transmission line accident detection circuit 5. The AND circuit 7 is configured to validate a trip command output from the trip command output circuit 18 when a logical product condition of the transmission line fault detection circuit 5 and the first current detection circuit 3 is satisfied.

[Operation] Next, the operation of the second embodiment having the above configuration will be described with reference to an example in which a voltage is applied to the shunt reactor 15b. That is, when a voltage is applied to the shunt reactor 15b, an inrush current flows. The transmission line fault detection circuit 5 does not operate if it is normal, but may malfunction for some reason. As described above, an increase in an error current due to saturation of a current transformer (not shown) that detects the current supplied to the fault detection circuit 5 and the generation of a surge current may cause a malfunction. ing. In any case, the current flowing through the shunt reactor 15b is a current value that does not cause a problem in the breaking performance of the shunt reactor switch 16b, and the first current detection circuit 3 detects this.

When a fault detection signal is output due to a malfunction of the transmission line fault detection circuit 5, the trip command output circuit 18 outputs a trip command to the shunt reactor switch 16b based on the fault detection signal. The AND circuit 7 determines that these conditions, that is, the logical product conditions of the transmission line fault detection circuit 51 and the first current detection circuit 3 have been met, and outputs the shunt reactor switch 16 from the trip command output circuit 18.
The trip command output to b is effective, and trips the shunt reactor switch 16b.

As described above, in the second embodiment, as in the first embodiment, the transmission line breakers 12a, 12b
However, the shunt reactor switches 16a and 16b are tripped instead of the side. At this time, the shunt reactor 15
In b, the current zero miss phenomenon has not occurred, the current has a zero point, and is equal to or less than the breaking performance of the shunt reactor switch 16b. Therefore, the shunt reactor switch 16b reliably shuts off this current. be able to. The above description has been given of the case where a voltage is applied to the shunt reactor 15b. However, the same operation is performed when a voltage is applied to the shunt reactor 15a or when a voltage is applied to the cable 13 and the shunt reactors 15a and 15b simultaneously. I do.

[Effect] As described above, according to the second embodiment, even if the transmission line fault detection circuit 5 malfunctions due to the shunt reactor rush current at the time of voltage application, the first current detection circuit 3 Is determined to be within the interrupting capability of the shunt reactor switches 16a and 16b, the trip command from the trip command output circuit 18 is made valid, and the shunt reactor switches 16a and 16b are tripped. Can be. At this time, the inrush current of the shunt reactors 15a and 15b due to the voltage application is equal to or less than the breaking performance of the shunt reactor switches 16a and 16b, and the AC component is not reduced at all as shown in FIG. So there is a zero current point. Therefore, the shunt reactor switch 16a,
There is no problem in opening the circuit 16b, and a reliable interruption is possible. As a result, the transmission line breakers 12a and 12b do not cut off the current having no current zero point, so that the interruption is not impossible and the development to the ground fault can be prevented.

As another case, there is a case where the transmission line fault detection circuit 5 operates normally and detects a fault in the transmission line 13. When an accident detection signal is output by the operation of the transmission line accident detection circuit 5, the trip command output circuit 18 outputs a shunt reactor switch 16a based on the accident detection signal.
A trip command is output to 16b. At this time, if the first current detection circuit 3 determines that the fault current is equal to or less than the current value at which the shunt reactor switches 16a and 16b can be cut off, the trip command from the trip command output circuit 18 is valid. Then, the shunt reactor switches 16a and 16b are tripped, and the shunt reactor switches 16a and 16b are tripped.
Can cut off a small fault current that is not more than the cutoff current value without any problem.

(3) Third Embodiment: Corresponding to Claims 3 and 4 [Structure] The third embodiment is a combination of Claims 3 and 4, and FIG. FIG. 3 is a block diagram of the embodiment. In FIG. 3, a conventional example shown in FIG.
The same parts as those in the first embodiment shown in FIG. 2 and the second embodiment shown in FIG. The configuration of the shunt reactor system is the same as that of the conventional example shown in FIG.

In the third embodiment, a shunt reactor fault detection circuit 1, a transmission line fault detection circuit 5, a second current detection circuit 8, and trip command output circuits 2 and 6 are provided. The second current detection circuit 8 is configured to detect that the current flowing through the shunt reactor switches 16a and 16b exceeds a current value that can be cut off by the shunt reactor switches 16a and 16b. I have. The transmission line fault detection circuit 5 detects a fault in the transmission line 13 for each phase and outputs a fault detection signal. The trip command output circuits 2 and 6 are configured to output a trip command to the transmission line breakers 12a and 12b in accordance with the accident detection signal, as in the conventional example.

Further, in the third embodiment, two A
ND circuits 9 and 10 are provided. A second current detection circuit 8 and a trip command output circuit 2 are connected to the AND circuit 9, and a second current detection circuit 8 and a trip command output circuit 6 are connected to the AND circuit 10. These AN
An OR circuit 11 is connected to the D circuits 9 and 10,
The R circuit 11 validates the trip command from the trip command output circuits 2 and 6 when the condition is satisfied.

[Operation] In the third embodiment having the above configuration, when a voltage is applied to the shunt reactors 15a and 15b and a fault occurs inside the shunt reactors 15a and 15b, a large fault current is generated. It may exceed the breaking performance of the flow and shunt reactor switches 16a and 16b. In this case, it is necessary to shut off the transmission line breakers 12a and 12b.

More specifically, the shunt reactors 15a,
If there is an accident inside 15b, the shunt reactor accident detection circuit 1 detects this and outputs an accident detection signal. The trip command output circuit 2 outputs a trip command to the transmission line breakers 12a and 12b based on the accident detection signal. An accident current generated due to an internal accident in the shunt reactors 15a and 15b flows through the shunt reactor switches 16a and 16b.
If the current value exceeds the cut-off current value of a and 16b, the second current detection circuit 8 performs a detection operation. That is, the AND condition of the shunt reactor fault detection circuit 1 and the second current detection means 8 in the AND circuit 9 is satisfied.

On the other hand, when there is an accident in the transmission line 13, the transmission line accident detection circuit 5 operates to output an accident detection signal, and based on the accident detection signal, the trip command output circuit 6 causes the transmission line breaker 12a. , 12b.
In addition, since there is a possibility that the zero current phenomenon may occur in the phases other than the fault phase, the transmission line fault detection circuit 5 detects a fault for each phase. The fault current generated by the fault in the transmission line 13 flows through the shunt reactor switches 16a and 16b.
If the current value exceeds the cut-off current value of a and 16b, the second current detection circuit 8 performs a detection operation. That is, in the AND circuit 10, the transmission line fault detection circuit 5 and the second current detection 8
The AND condition of the circuit is satisfied.

In the OR circuit 11, if the logical sum condition is satisfied, that is, if either of the AND circuits 9 and 10 is satisfied, the output from the trip command output circuits 2 and 6 to the transmission line circuit breakers 12a and 12b. The trip command thus issued is valid, and the transmission line breakers 12a and 12b can be tripped.

[Effect] According to such a third embodiment, when the shunt reactor fault detection circuit 1 or the transmission line fault detection circuit 5 operates, the shunt reactor switches 16a and 16b flow. If the second current detection circuit 8 detects that the current exceeds the cutoff current value of the shunt reactor switches 16a and 16b, the shunt reactor switches 16a and 16b are used instead of the shunt reactor switches 16a and 16b. The electric circuit breakers 12a and 12b are cut off. If the interrupting current is large enough to exceed the interruptable current value of the shunt reactor switches 16a, 16b, it is erroneous to assume that an accident has occurred in the shunt reactors 15a, 15b or the transmission line 13. Absent.

That is, the shunt reactors 15a, 1
Since an accident has occurred in the transmission line 5b or the transmission line 13, the zero current failure phenomenon has not occurred in the transmission line breakers 12a and 12b. Accordingly, the power line breakers 12a,
The current interrupted by 12b has a current zero point, and the power line breakers 12a and 12b can reliably shut off the fault current while maintaining excellent interrupting performance.

(4) Fourth Embodiment—corresponding to Claim 5 [Configuration] A fourth embodiment corresponding to claim 5 will be specifically described with reference to the block diagram of FIG. The fourth embodiment includes a shunt reactor accident detection circuit 1
, Trip command output circuit 2 and second current detection circuit 8
And an AND circuit 19. AND circuit 1
9 is a trip command output circuit 2 and a second current detection circuit 8
, And is configured to transfer a trip command from the trip command output circuit 2 to the transmission line breaker 12a (12b) at the opposite end when detecting that both circuits 2 and 8 are established. ing.

[Operation] In the fourth embodiment, for example, a voltage is applied to the shunt reactor 15b,
When there is an accident inside the shunt reactor 15b, a large accident current flows, which may exceed the breaking performance of the shunt reactor switch 16b. In this case, the second current detection circuit 8 detects that the magnitude of the fault current exceeds a current value that can be cut off by the shunt reactor switch 16b,
In the D circuit 19, a logical product condition of the shunt reactor fault detection circuit 1 and the second current detection means 8 is satisfied. As a result, from the trip command output circuit 2 to the transmission line breaker 12b
The trip command output to is valid, and the transmission line breaker 12b can be tripped. At the same time, AN
The D circuit 19 transfers the trip command to the transmission line breaker 12a at the opposite end, and can trip this.

[Effects] According to the fourth embodiment, the circuit breakers 12a, 1 at both ends of the transmission line 13 are provided.
Both 2b can be quickly tripped.
This makes it possible to further enhance the safety and reliability of the shunt reactor system.

(5) Other Embodiments The present invention is not limited to the above-described embodiments, and the configuration and the number of components of each member can be appropriately changed. The inventions of claims 1 to 4 can be implemented alone or in combination.

[0059]

As described above, according to the shunt reactor system protection device of the present invention, even when the accident detection means malfunctions when a voltage is applied to the shunt reactor and an inrush current flows, Detects that the current flowing through the shunt reactor switch is equal to or less than the current value that can be interrupted by the shunt reactor switch, and detects that the current is not flowing through the transmission line breaker without a zero point. By tripping the switchgear, it is possible to completely prevent the failure of the circuit breaker for the transmission line to be cut off, thereby preventing the occurrence of a ground fault and improving safety and reliability.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a third embodiment of the present invention.

FIG. 4 is a block diagram of a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a shunt reactor system.

FIG. 6 is a block diagram of a conventional protection device for a shunt reactor system.

FIG. 7 is a block diagram of a conventional protection device for a shunt reactor system.

8 is a graph showing the relationship between the inrush current and the charging current, wherein (a) shows the charging current, (b) shows the inrush current, and (c) shows the zero point transition current.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shunt reactor accident detection circuit 2, 6, 17, 18 ... Trip command output circuit 3 ... 1st current detection circuit 4, 7, 9, 10, 19 ... AND circuit 5 ... Transmission line accident detection circuit 8 ... 2 Current detection circuit 11 ... OR circuit 12a, 12b ... Circuit breaker for transmission line 13 ... Transmission line 14 ... Capacitance of transmission line 15a, 15b ... Shunt reactor 16a, 16b ... Switch for shunt reactor

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Saida 1-1-1, Shibaura, Minato-ku, Tokyo F-term in Toshiba head office (reference) 5G053 AA01 BA01 CA01 FA07

Claims (5)

[Claims] 1. A shunt reactor for compensating a charging current of a transmission line, a shunt reactor switch for connecting the shunt reactor to the transmission line in parallel, and the transmission line and the shunt reactor collectively. A shunt reactor system configured to include a transmission line circuit breaker that shuts off the shunt reactor, the shunt reactor accident detection means for detecting an internal accident of the shunt reactor and outputting an accident detection signal, A trip command output means for outputting a trip command to the shunt reactor switch based on the accident detection signal; and a current flowing through the shunt reactor switch is equal to or less than a current value at which the shunt reactor switch can be shut off. A first current detecting means for detecting that the shunt reactor accident detecting means and the first current detecting means have a logical product condition. Tsu protection device of shunt reactor system, characterized in that it is configured to validate the output trip command to the flop command output means. 2. A shunt reactor for compensating a charging current of a transmission line, a shunt reactor switch for connecting the shunt reactor to the transmission line in parallel, and the shunt reactor and the shunt reactor collectively. A transmission line breaker comprising a circuit breaker for a transmission line that cuts off and disconnects the transmission line, the transmission line failure detection means for detecting a failure of the transmission line and outputting a failure detection signal, and the failure detection signal A trip command output means for outputting a trip command to the shunt reactor switch based on: a current flowing through the shunt reactor switch is equal to or less than a current value that can be cut off by the shunt reactor switch. And a first current detecting means for detecting the current is output from the trip command output means when a logical product condition of the transmission line fault detecting means and the first current detecting means is satisfied. Protection device of shunt reactor system, characterized in that it is configured so as to enable the lip command. 3. A shunt reactor for compensating a charging current of a transmission line, a shunt reactor switch for connecting the shunt reactor to the transmission line in parallel, and the shunt reactor and the transmission line collectively. A shunt reactor system configured to include a transmission line circuit breaker that shuts off the shunt reactor, the shunt reactor accident detection means for detecting an internal accident of the shunt reactor and outputting an accident detection signal, A trip command output unit that outputs a trip command to the transmission line circuit breaker based on an accident detection signal, and a current flowing through the shunt reactor switch exceeds a current value that can be cut off by the shunt reactor switch. And a second current detecting means for detecting that the trip finger is detected when a logical product condition of the shunt reactor accident detecting means and the second current detecting means is satisfied. Protection device of shunt reactor system, characterized in that it is configured so as to enable the trip command output by the output means. 4. A shunt reactor for compensating a charging current of a transmission line, a shunt reactor switch for connecting the shunt reactor to the transmission line in parallel, and the transmission line and the shunt reactor collectively. A transmission line breaker configured to include: a transmission line circuit breaker configured to interrupt the transmission line; anda transmission line accident detection unit that outputs an accident detection signal by detecting an accident of the transmission line for each phase. Trip command output means for outputting a trip command to the transmission line circuit breaker based on the accident detection signal, and a current flowing through the shunt reactor switch determines a current value at which the shunt reactor switch can be interrupted. A second current detecting means for detecting that the current value exceeds the threshold, and outputting the trip command output means when a logical product condition of the transmission line fault detecting means and the second current detecting means is satisfied. Protection device of shunt reactor system, characterized in that it is configured so as to enable the lip command. 5. The circuit breaker for a transmission line to which the trip command is output when the trip command output from the trip command output means is valid, wherein the circuit breaker for the transmission line is disposed at both ends of the transmission line. 5. The shunt reactor system protection device according to claim 3, further comprising transfer trip command output means for transferring a trip command to a transmission line breaker disposed at an opposite end of the shunt reactor.