JP3172988B2 - Gas circuit breaker failure detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas circuit breaker and a gas circuit breaker for detecting a fault when a ground fault or a short circuit fault occurs in a gas circuit breaker such as a gas breaker of a gas insulated switchgear. A failure detection device.

[0002]

2. Description of the Related Art Generally, a gas circuit breaker or a circuit breaker gas section of a gas insulated switchgear is formed by housing a circuit breaker in a metal container and sealing an insulating gas such as sulfur hexafluoride gas. It is excellent in miniaturization, high reliability and safety. However, if a ground fault or short-circuit fault occurs inside the gas circuit breaker, the fault is detected by the protection relay so that the fault does not continue. The gas circuit breaker cannot be specified. Further, since the gas circuit breaker has a closed structure, it is difficult to visually check the gas circuit breaker in which a failure has occurred from the outside. For this reason, when a ground fault or a short circuit fault occurs, the gas pressure of the insulating gas increases due to the fault arc energy. Therefore, a failure of the gas circuit breaker may be detected by detecting the pressure increase. In this failure detection device, a pressure sensor is conventionally provided in a gas circuit breaker, and the pressure sensor measures the pressure value of the insulating gas. Then, a pressure rise value is obtained from a difference between the pressure value, which is the output of the pressure sensor, and the sealed pressure value, and when the pressure rise value exceeds a preset monitoring value, a failure is determined. I have.

[0003] Further, in a gas insulated switchgear, the inside thereof is usually divided into a plurality of gas compartments such as a breaker gas compartment and a disconnector gas compartment, and a failure occurs from the viewpoint of stable power supply. It is necessary to quickly restore a healthy gas section other than the gas section and that does not hinder the application of voltage, and to shorten the power outage time. Therefore, in order to detect a faulty partition, a faulty partition detection device may be used, and the output of the faulty detection device is also used as one input of the faulty partition detection device.

[0004]

The above-mentioned conventional failure detecting device has the following problems. If a ground fault or short circuit fault occurs inside the gas circuit breaker, the gas pressure rises at the fault arc energy. In addition, the protection relay operates so that the failure does not continue, and the circuit breaker is opened by the circuit breaker opening command signal, and the arc between the contacts of the circuit breaker at the time of opening, that is, the circuit breaker opening arc is generated. Then, the gas pressure also increases due to the arc energy. On the other hand, if a ground fault or short-circuit fault occurs other than the gas circuit breaker,
Since it is not a failure inside the gas circuit breaker, there is no increase in gas pressure due to the failed arc, but the protection relay operates so that failures other than the gas circuit breaker do not continue, and the circuit breaker opening command signal Since the gas circuit breaker is opened, a circuit breaker opening arc is generated, and the gas energy is increased by the arc energy. For this reason, in the conventional failure detection device that determines a failure by detecting the level of the pressure rise, it is not possible to distinguish whether the detected pressure rise is due to the faulty arc or to the circuit breaker opening arc, and the gas circuit breaker cannot be distinguished. Failure cannot be detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a failure detection device for a gas circuit breaker that can correctly detect a failure even when a pressure rise due to a breaker opening arc occurs.

[0006]

SUMMARY OF THE INVENTION A pressure sensor for detecting the gas pressure is provided in a gas circuit breaker in which an insulating gas is sealed. A protection relay operation detection unit for detecting a protection relay operation signal from the protection relay is provided. The protection relay operation time is detected from the output of the protection relay operation detection unit, and at that time, the circuit breaker opening time and the time when the pressure rise due to the circuit breaker opening arc reaches the pressure sensor from the opening arc position to the pressure sensor. Is provided. A pressure rise time detection unit for obtaining a pressure rise time from the output of the pressure sensor is provided. When the pressure rise time obtained by the pressure rise time detection unit is earlier than the time obtained by the protection relay operation time correction unit, a determination unit for determining that the gas circuit breaker has failed is provided.

[0007]

According to the present invention, as described above, the presence or absence of a pressure increase before the pressure increase of the breaker opening arc by the protection relay reaches the pressure sensor is checked. Is determined. That is, the time at which the pressure rise of the circuit breaker opening arc reaches the pressure sensor is the protection relay operation correction time obtained by the protection relay operation time correction unit. This is the time obtained by adding the time and the time when the pressure rise due to the circuit breaker opening arc propagates through the insulating gas and reaches the pressure sensor from the opening arc position. On the other hand, the pressure rise time obtained by the pressure rise time detection unit is the time at which the pressure rise due to the faulty arc propagates through the insulating gas and reaches the pressure sensor from the position of the faulty arc. It is before the protection relay operation correction time obtained by the time correction unit. Therefore, it is possible to distinguish between a pressure increase due to a failed arc and a pressure increase due to a circuit breaker opening arc, and determine that a sound gas circuit breaker is not a failure and only a failed gas circuit breaker is a failure. Further, since the failure is determined based on the protection relay operating condition, that is, the failure occurrence condition, even if a pressure rise due to an arc between the contacts at the time of opening / closing operation of the breaker when the protection relay does not operate normally,
Since this is not determined as a failure, erroneous determination can be prevented.

[0008]

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows the case of a circuit breaker gas section of a gas insulated switchgear. In FIG. 1, the electrical connection of the main circuit of the circuit breaker gas section 1 of the gas insulated switchgear is shown in a single-line connection diagram, and 11 is a circuit breaker,
Reference numeral 12 denotes a conductor. A current transformer 13 is provided on one side of the circuit breaker 11, and its output is input to the protection relay 5. Also,
The circuit breaker opening command signal of the protection relay 5 is output to the circuit breaker 11 in the circuit breaker gas section 1. A pressure sensor 2 for detecting a gas pressure is provided in a circuit breaker gas section 1, and a pressure rise time detecting section 3 is provided on an output side thereof. A protection relay operation detection unit 6 for detecting a protection relay operation signal from the protection relay 5 is provided, and a protection relay operation time correction unit 7 is provided on an output side thereof. A determination unit 4 is provided on the output side of the pressure rise time detection unit 3. The output of the protection relay operation time correction unit 7 is input to the determination unit 4.

The pressure rise time detecting section 3 measures a pressure rise value from a change in the output of the pressure sensor 2, and detects a time point when the pressure rise value becomes equal to or more than a predetermined monitoring value for detecting a pressure rise. Detects the pressure rise time and determines the time.
Output to The protection relay operation time correction unit 7 detects the protection relay operation from the protection relay 5 detected by the protection relay operation detection unit 6 and obtains the operation time of the protection relay 5.
At the operation time of the protection relay 5, the opening time of the circuit breaker 11 and the time when the pressure rise due to the opening arc of the circuit breaker 11 reaches the pressure sensor 2 from the opening arc position, that is, the opening arc of the circuit breaker 11 The time obtained by adding the propagation delay time of the pressure rise due to the above is obtained, and the obtained time is output to the determination unit 4 as the protection relay operation correction time. The propagation delay time of the pressure increase due to the fault arc changes because the position of the fault arc in the circuit breaker gas compartment 1 is not constant, but the propagation delay time of the pressure rise due to the opening arc of the circuit breaker 11 is It does not change because the position of the pole arc is constant. For this reason, the propagation delay time of the pressure increase due to the opening arc of the circuit breaker 11 to be added can be obtained and set in advance.

For example, the protection relay operation time correction time of the protection relay operation time correction unit 7 is obtained by setting the opening time of the circuit breaker 11 to 25.
Assuming that the propagation delay time of the pressure rise due to the opening arc of the circuit breaker 11 is 10 ms, the operation time of the protection relay 5 detected by the protection relay operation detection unit 6 is 25 ms and 10 ms.
Is added to the time. The propagation delay time of the pressure increase due to the opening arc of the circuit breaker 11 is, for example, when the insulating gas in the circuit breaker gas compartment 1 is sulfur hexafluoride gas.
We ask as follows. The distance in the insulating gas from the opening arc position of the circuit breaker 11 to the mounting position of the pressure sensor 2 is obtained by dividing by the pressure propagation speed in the insulating gas. Here, the pressure propagation velocity in the insulating gas is substantially equal to the sound velocity in the insulating gas, and is about 130 m / s. The above-mentioned propagation delay time 10 ms of the pressure rise is when the distance in the insulating gas from the opening arc position of the circuit breaker 11 to the mounting position of the pressure sensor 2 is 1.3 m, and the pressure propagation speed is 130 m / s. .

The judging section 4 compares the pressure rise time from the pressure rise time detection section 3 with the protection relay operation correction time from the protection relay operation time correction section 7 and determines that the pressure rise time is earlier than the protection relay operation correction time. The gas breaker gas compartment 1
Is determined as a failure, and the result of the determination is output.

Next, the operation of the present invention will be described. The operation in the case where a ground fault or short circuit fault occurs in the circuit breaker gas section 1 will be described below. When a fault occurs in the circuit breaker gas compartment 1, a fault current is detected by the current transformer 13 and the protection relay 5
Outputs a protection relay operation signal and outputs a circuit breaker opening command signal to the circuit breaker 11 of the circuit breaker gas section 1;
The circuit breaker 11 in the circuit breaker gas compartment 1 operates to open the electrode. Note that the protection relay operation signal and the circuit breaker opening command signal from the protection relay 5 are output after the protection relay operation time of the protection relay 5 from the occurrence of the failure. For this reason, in the circuit breaker gas section 1, the pressure first rises due to the faulty arc. After that, the circuit breaker 11 of the circuit breaker gas compartment 1 is opened by the circuit breaker opening command signal from the protection relay 5.
An arc between the contacts of the circuit breaker 11 is generated, and the pressure increases due to the opening arc. The pressure sensor 2 detects these increased gas pressures. Pressure rise time detector 3
Then, the pressure rise value is measured from the change in the output of the pressure sensor 2, the pressure rise value is compared with a monitoring value for pressure rise detection determined in advance from the pressure rise value due to the failed arc, and the measured pressure rise value is measured. Is greater than or equal to the monitored value, it is determined that the pressure has risen, and the time at that time is taken as the pressure rise time. For this reason, the pressure rise time detecting unit 3
Of the pressure rise due to the faulty arc, not the pressure rise due to the opening arc. This pressure rise time is a time obtained by adding the propagation delay time of the pressure rise determined by the distance between the failure arc occurrence position and the mounting position of the pressure sensor 2 to the failure occurrence time.

On the other hand, based on the protection relay operation signal from the protection relay 5 detected by the protection relay operation detection unit 6, the protection relay operation correction time obtained by the protection relay operation time correction unit 7 is based on the failure occurrence time. This time is a time obtained by adding the protection relay operating time of the protection relay 5, the opening time of the circuit breaker 11, and the propagation delay time of the pressure rise due to the opening arc of the circuit breaker 11. Therefore, when the pressure rise time from the pressure rise time detection unit 3 is before the protection relay operation time of the protection relay 5, the determination unit 4 determines that the circuit breaker gas section 1 is out of order and outputs the result. Further, even when the failure arc occurrence position is far from the mounting position of the pressure sensor 2, the propagation delay time of the pressure rise becomes longer, and the pressure rise time from the pressure rise time detector 3 becomes after the protection relay operation time, If it is before the protection relay operation correction time obtained by the protection relay operation time correction unit 7, the circuit breaker gas compartment 1 is determined to be faulty and the result is output.

The opening time 2 of the circuit breaker 11 in the above example is 2
When the propagation delay time of the pressure rise due to the opening arc of the circuit breaker 10 is 5 ms and the failure arc detection position at which the failure can be detected by the determination unit 4 is obtained as follows:
Here, it is assumed that the protection relay operation time of the protection relay 5 is 25 ms. The time at which the pressure rise due to the opening arc of the circuit breaker 11 reaches the pressure sensor 2 is based on the failure occurrence time, at which time the protection relay operating time of the protection relay 5 is 25 ms, and the time at which the circuit breaker 11 is opened. This time is 60 ms after adding 25 ms and the propagation delay time 10 ms of the pressure rise due to the opening arc of the circuit breaker 11. This means that a failure can be detected if the time at which the pressure rise of the failed arc reaches the pressure sensor 2 is earlier than the time when 60 ms is added to the failure occurrence time. For this reason, the propagation delay time of the pressure rise due to the fault arc in which the fault can be detected is less than 60 ms. This 60 ms and pressure propagation speed 1
From 30 m / s, the distance from the failed arc occurrence position to the mounting position of the pressure sensor 2 is 7.8 m.
Therefore, if the fault arc occurrence position is less than 7.8 m from the mounting position of the pressure sensor 2, the fault can be detected.

Next, a case will be described in which a failure occurs outside the circuit breaker gas compartment 1, the circuit breaker 11 is opened, and only the pressure increase of the circuit breaker opening arc occurs in the circuit breaker gas compartment 1. If a fault occurs in any part other than the breaker gas section 1, a fault current is detected in the current transformer 13, and the protection relay 5 outputs a protection relay operation signal and opens the circuit breaker to the circuit breaker 11 in the breaker gas section 1. A pole command signal is output, and the circuit breaker 11 of the circuit breaker gas section 1 operates to open the pole. Therefore, in the circuit breaker gas section 1, there is no pressure increase due to the faulty arc, but the circuit breaker 11 of the circuit breaker gas section 1 is opened by the circuit breaker opening command signal from the protection relay 5, so that the circuit breaker 1
One inter-contact arc is generated, and the pressure increases due to the opening arc. The pressure sensor 2 detects the increased gas pressure. The pressure rise time detection unit 3 measures a pressure rise value from a change in the output of the pressure sensor 2 and compares the pressure rise value with a monitoring value for pressure rise detection determined in advance from a pressure rise value due to a failed arc. When the measured pressure rise value is equal to or more than the monitoring value, it is determined that the pressure rise is “present”, and the time at that time is output as the pressure rise time.
For this reason, if the pressure rise value due to the opening arc of the circuit breaker 11 is equal to or greater than the monitoring value for pressure rise detection, the pressure rise time detection unit 3 detects the pressure rise time. This pressure rise time is a time obtained by adding the opening time of the circuit breaker 11 and the propagation delay time of the pressure rise due to the opening arc of the circuit breaker 11 to the operation time of the protection relay 5, that is, the protection relay operation time correction unit. This is the protection relay operation correction time obtained in step 7. Therefore, since the pressure rise time from the pressure rise time detection unit 3 is not before the protection relay operation correction time from the protection relay operation time correction unit 7, the determination unit 4 does not determine that the circuit breaker gas compartment 1 has failed. No fault is output. If the pressure rise value due to the opening arc of the circuit breaker 11 is less than the monitoring value for pressure rise detection, the pressure rise time detection unit 3 determines that there is no pressure rise and does not output the pressure rise time. The determination unit 4 does not make a failure determination, and the circuit breaker gas compartment 1
Does not output as failure.

As described above, the pressure rise caused by the faulty arc generated in the circuit breaker gas compartment 1 and the pressure rise caused by the opening arc of the circuit breaker 11 can be distinguished, and only the pressure rise caused by the faulty arc can be detected. it can.

When the circuit breaker 11 of the circuit breaker gas section 1 is normally opened and closed, a pressure rise occurs due to the arc between the contacts, but the protection relay 5 does not operate because it is not a failure. Therefore, since the protection relay operation time correction unit 7 does not receive the protection relay operation signal from the protection relay 5 via the protection relay operation detection unit 6, the protection relay operation correction time is not output to the determination unit 4. No. 4 does not judge a failure, and no failure is erroneously output.

In the above, the embodiment has been described with respect to the case of the gas breaker gas section of the gas insulated switchgear. In the case of the gas circuit breaker, similarly, a failure can be correctly detected.

[0019]

As described above, according to the present invention, a failure is determined by the presence or absence of a pressure increase before the pressure increase of the breaker opening arc by the protection relay reaches the pressure sensor. Therefore, the pressure rise due to the failed arc is distinguished from the pressure rise due to the opening arc when the circuit breaker is opened, and the sound gas circuit breaker is not automatically determined to be faulty, but the faulty gas circuit breaker is automatically determined to be faulty. be able to. In addition, since the failure is determined based on the protection relay operating conditions, even if the pressure rise due to the arc between the contacts during switching operation of the breaker during normal operation when the protection relay does not operate, it is not determined to be a failure. In addition, erroneous detection can be prevented. Further, even when the propagation delay time of the pressure rise is long and the pressure rise due to the faulty arc occurs after the protection relay operation, the pressure rise can be detected and the fault can be correctly detected.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit breaker gas compartment 2 Pressure sensor 3 Pressure rise time detection part 4 Judgment part 5 Protection relay 6 Protection relay operation detection part 7 Protection relay operation time correction part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 33/00 H01H 33/56 H02B 13/065

Claims (1)

(57) [Claims] 1. A pressure sensor for detecting a gas pressure provided in a gas circuit breaker in which an insulating gas is sealed, a protection relay operation detection unit for detecting a protection relay operation signal from a protection relay, The protection relay operation time is detected from the output of the protection relay operation detection unit, and at that time, the circuit breaker opening time and the time when the pressure rise due to the circuit breaker opening arc reaches the pressure sensor from the opening arc position. A protection relay operation time correction unit for obtaining a time obtained by adding the above, a pressure rise time detection unit for obtaining a pressure rise time from an output of the pressure sensor, and a pressure rise time obtained by the pressure rise time detection unit,
A failure detection device for a gas circuit breaker, comprising: a determination unit that determines that the gas circuit breaker has failed if the current time is before the time obtained by the protection relay operation time correction unit.