JP3184206B2 - Power equipment, power transmission and distribution unit and trip method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power device, and more particularly, to a power device, a power transmission / distribution unit, and a tripping method thereof capable of diagnosing insulation abnormality due to foreign matter inside the device.

[Conventional technology]

In recent years, demand for electric power has been increasing year by year, and social living environments using electricity have become widespread, and high-quality electric power supply has become a social demand. This high-quality power supply means that there is no power failure and there is little fluctuation in voltage and frequency. For this reason,
Power equipment is required to have few failures. For power equipment, for example, circuit breakers, transformers, buses, etc. that are insulated with SF ₆ gas, the high-voltage parts are housed in a sealed container, so abnormalities inside this equipment can be found visually during inspection. It is difficult.

For this reason, various preventive maintenance measures for detecting an abnormality of the device in advance have been proposed. As one example,
As disclosed in Japanese Patent Application Laid-Open No. 55-37868, several levels of alarms are detected in accordance with the levels detected by the detectors.

[Problems to be solved by the invention]

This kind of preventive maintenance measures mainly focuses on how to accurately detect signals related to partial discharge, and estimates the shape and position of foreign objects that move due to the action of an electric field in power equipment, and No abnormality has been detected, and the subsequent processing measures for power equipment have not been considered. For this reason, there has been a problem that the maintenance staff of the power equipment falls into a state of confusion about the corresponding processing.

An object of the present invention is to provide a shape of a foreign substance moving in a power device,
An object of the present invention is to provide a power device, a power transmission / distribution unit, and a trip method capable of estimating a position situation, determining an abnormal state of the power device, and appropriately instructing a corresponding process.

[Means for solving the problem]

In order to achieve the above object, the present invention relates to a power device having a conductor in a container, wherein the container includes a foreign substance which is present in the container and which may move in the container by the action of an electric field and induce an insulation abnormality. A first sensor that detects a collision sound to the second sensor, a second sensor that detects a partial discharge generated in the container, and a diagnostic unit that diagnoses a state of a foreign substance in the container. Based on the detection signal of the first sensor, it is determined whether or not foreign matter is present on the container side, and the detection frequency signal obtained based on the detection signal of the second sensor is compared with the set reference frequency signal. It is characterized in that the occurrence of partial discharge in the container is determined based on the result of the magnitude comparison, and the state of the foreign matter in the container is diagnosed based on the determination result.

In addition, the diagnosis unit may include: (1) when a foreign substance is not present on the container side based on the detection signal of the first sensor and the detection frequency signal is smaller than the reference frequency signal, a small foreign substance adheres to the conductor; (2) When a foreign substance is present on the container side based on the detection signal of the first sensor and the detection frequency signal is smaller than the reference frequency signal, a foreign substance having a length exists on the container side. (3) If a foreign substance is present on the container side based on the detection signal of the first sensor and the detection frequency signal is higher than the reference frequency signal, the foreign substance floats and falls between the container and the conductor. (4) When a foreign substance is present on the container side based on the detection signal of the first sensor and the detected frequency signal is larger than the reference frequency signal, ( And (5) no foreign matter is present on the container side based on the detection signal of the first sensor, and the detection frequency signal is higher than the reference frequency signal. If the size is larger, it is diagnosed that a foreign substance longer than the foreign substance in the case (1) exists on the conductor side, and an emergency stop command is output based on the diagnosis result.

In addition, a display unit or an alarm is provided, and the diagnosis result is displayed on the display unit or the alarm is alarmed based on an emergency stop command of the diagnostic unit.

To achieve the above object, the present invention provides a conductor connected to a power system and supported by an insulating spacer,
In a power transmission unit configured to include at least a connection bus bar, a disconnector, a transformer, a circuit breaker, and a lightning arrester connected to the conductor, at least one of the devices includes:
A first sensor that detects a collision sound of a foreign object with a container constituting the device, a second sensor that detects a partial discharge generated in the container, and a diagnostic unit that diagnoses a state of the foreign object in the container, A device for disconnecting the unit from the power system based on the trip command signal output from the diagnostic unit, wherein the diagnostic unit determines whether or not foreign matter is present on the container side based on the detection signal of the first sensor. And determining the occurrence of partial discharge in the container based on the magnitude comparison result of the detection frequency signal obtained based on the detection signal of the second sensor and the set reference frequency signal, and The state of the foreign matter in the container is diagnosed based on these determination results, and the trip command signal is output based on the diagnosis result.

To achieve the above object, the present invention provides a conductor connected to a power system and supported by an insulating spacer,
In a method of tripping a power transmission unit including at least a connection bus bar, a disconnector, a transformer, a circuit breaker, and a lightning arrester connected to the conductor, collision of foreign matter with a container constituting at least one of the devices The sound is detected by the first sensor, the partial discharge occurring in the container is detected by the second sensor, and it is determined whether or not foreign matter is present on the container side based on a detection signal of the first sensor. The occurrence of partial discharge in the container is determined based on a magnitude comparison result between a detection frequency signal obtained based on a detection signal of the second sensor and a set reference frequency signal, and based on these detection results, Diagnose the state of foreign matter in the container, determine whether the emergency stop of the power transmission unit is possible or impossible based on the diagnosis result. If the emergency stop is not possible by outputting a power command signal to the power transmission unit and the emergency stop is not possible, the power system is shifted to a state capable of emergency stop by system operation and the power transmission unit is switched from the power system. Is separated.

[Action]

The power device configured as described above is a device that outputs a determination result based on detection signals of the first sensor and the second sensor.
The position state is estimated, insulation abnormality due to foreign matter is determined, and the determination result is output.

Also, the diagnostic device diagnoses the insulation state due to foreign matter inside the equipment container, and displays the diagnostic result on a display,
Alternatively, an alarm is issued and both signals are generated.

Also, the device that outputs the trip command signal determines the presence of the insulation abnormality, and outputs a trip command signal to the trip device based on the result of the determination. As a result, the trip unit disconnects the power transmission / distribution unit from the grid or stops the unit.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 illustrates a gas insulated switchgear which is an example of the power equipment of the present invention. In FIG. 1, a gas insulated switchgear 1 includes various switchgears such as a circuit breaker 9 in a container 3 having a ground potential, and is provided with a SF ₆ having excellent insulation performance and arc extinguishing performance.
Insulating gas such as gas is sealed. The electric power is guided from the overhead wire 4 through the bushing 5 into the equipment, and a bus composed of the conductor 7 supported by the insulating spacer 6.
It is sent to the transformer 10 via the disconnector 8, the circuit breaker 9, and the like. A light protector 11 for suppressing an overvoltage is attached near the entrance of the overhead wire 4. This gas insulated switchgear 1 is connected to a system and constitutes a power transmission and distribution unit.

Next, an example of a diagnostic device attached to the gas insulated switchgear 1 will be described.

The container 3 of the gas insulated switchgear 1 described above includes a plurality of first sensors 12a and 12b for detecting a collision sound of foreign matter in the container 3 with the container, and detecting a partial discharge generated inside the container 3. A second sensor 13 is provided. The first mentioned above
As the sensors 12a and 12b, for example, an ultrasonic microphone is used. The first sensors 12a and 12b include two types of sensors having different detection frequency bands in order to prevent malfunction caused by vibration generated when a raindrop or the like collides with the container 3.
It may be used as an individual. The second sensor 13 is, for example, a second sensor.
As shown in the figure, an electrode 133 is attached to a cover 131 in a handhole 130 of the container 3 via an insulator 132, and a lead 135 is connected to the electrode 133 through an insulating piece 134. With this configuration, an electric pulse due to partial discharge is detected by dividing the capacitance by the capacitance between the conductor 7 and the electrode 133 and the capacitance between the electrode 133 and the cover 131.
Further, as a detection means based on this kind of capacitance, the detection may be performed by using the capacitance of the insulating spacer 10, or the partial discharge current may be detected from a ground wire connected to the container 3. Is also good. The second sensor 13 detects the partial discharge of the frequency components of 500~1500MHz generated inside the container 3 is insulated with SF ₆ gas.

Returning to FIG. 1, the first sensors 12a, 12b are connected to amplifiers 14a, 14b, respectively. The amplifiers 14a and 14b are connected to the signal processing units 15a and 15b, respectively. Signal processing unit 15a, 1
5b is connected to the diagnostic unit 16. The second sensor 13 is connected to an amplifier 17. The amplifier 17 is connected to the frequency analyzer 18. The frequency analyzer 18 analyzes the frequency of the signal detected by the second sensor 13. This frequency analysis unit 18 is connected to the signal comparison unit 19. Signal comparison unit 19
Is connected to a reference frequency generator 20. In the reference frequency generating section 20, a value in the frequency component of the partial discharge of 500 to 5000 MHz described above, for example, a reference frequency of 1000 MHz which is an intermediate value, and a reference frequency signal at this reference frequency is set. The reference frequency signal is output to signal comparing section 19. The signal comparison unit 19 compares the magnitude of the reference frequency signal output from the reference frequency generation unit 20 with the detection frequency signal output from the second sensor 13 and at the same detection frequency as the reference frequency. The diagnosis unit 16 is connected to output a determination signal indicating whether the detection frequency signal is larger or smaller than the reference frequency signal. Diagnosis unit 16
Detects that there is a foreign substance in the container 3 based on one of the signals from the first sensors 12a and 12b, and outputs the frequency from the signal comparing section 19 related to the detected frequency signal of the second sensor 13. The occurrence of partial discharge due to the needle-like electrode-like foreign matter is detected based on the signal determined to be larger or smaller, and a diagnosis result is determined based on the detection result. Table 1 summarizes the relationship between the detection result in the diagnosis unit 16 and the diagnosis result obtained based on this result. The diagnosis unit 16 compares the magnitudes of the detection signals of the first sensors 12a and 12b at the same time, and detects the position of the foreign matter in the container 3 in the axial direction based on the comparison result. be able to.

Further, based on the diagnostic results shown in Table 1, the diagnostic unit 16
According to the processing steps shown in FIG. 5, the corresponding processing contents are output to the display unit 21.

The reason why a diagnosis result is obtained from the detection results shown in Table 1 described above will be described below.

As shown by the corresponding number 1 in Table 1, the foreign matter is
When the internal partial discharge is not occurring, the foreign matter is present on the ground side where the electric field is low, and thus the power device can be continuously used while strengthening the monitoring.

In the case of Correspondence No. 2 in Table 1, that is, when the foreign matter adheres to the conductor 7 and generates a small internal discharge, the relationship between the length of the foreign matter and the corona generation voltage and flash voltage shown in FIG. As can be seen from the above, it can be determined that a small foreign substance has adhered to the conductor 7 having a high electric field, and the state has become extremely dangerous.
In FIG. 3 described above, the specific curve A indicates the corona generation voltage, and the characteristic curve B indicates the flash voltage.

In the case of the correspondence number 3 in Table 1, that is, when the foreign matter is on the container 3 side and a small internal discharge is generated,
As is clear from the characteristics of the foreign matter length and the corona generation voltage when the foreign matter shown in FIG. 4 is present on the container side, the foreign matter having a length exists on the inner surface of the container 3 like a needle electrode. It can be determined that there is. Therefore, even during normal operation, lightning surge,
With the intrusion of the switching surge, the degree of danger of flashing of the device can be known.

In the case of the corresponding numbers 4 and 5 in Table 1, based on the detection result, foreign matter attached to the conductor 7 initially causes internal partial discharge, and the foreign matter repeatedly floats and drops, or there are many foreign matters. You can judge that you are doing. In this case, it can be said that the situation is dangerous.

In the case of the correspondence number 6 in Table 1, a large value of the internal partial discharge is generated, and the foreign matter is on the container 3 side.
From FIG. 4, it can be determined that a foreign substance having a further length is forming a needle-shaped electrode, which can be said to be a dangerous state.

Furthermore, in the case of the correspondence number 7 in Table 1, contrary to the case of the correspondence number 6 described above, it can be determined that a foreign substance having a length exists as the needle electrode on the conductor 7 side having a high electric field, In this case as well, there is a danger to the intrusion of high voltage.

Although not shown in Table 1, even in the case of the corresponding number 1 in Table 1, a dangerous state may occur depending on the position of the foreign matter. That is, in a gas insulated substation device, a charged part such as a conductor is a sealed container that encloses an insulating gas (generally, a metal container is used for convenience of manufacture and grounded to prevent electric shock due to induction). Because it is supported inside, an insulating spacer 10 is used. If a conductive foreign substance or a substance having a dielectric constant different from that of the insulating spacer adheres to the surface of the insulating spacer 10, the electric field on the surface is disturbed, so that electric field concentration occurs, and the insulation performance is greatly reduced. In order to prevent the danger in this case, it is detected whether or not a foreign substance is located near the insulating spacer 10 based on signals from the first sensors 12a and 12b, and the degree of danger of flashing of the device due to the foreign substance is determined. You can also.

Next, the operation of the embodiment of the present invention will be described with reference to a flowchart shown in FIG.

When the diagnostic unit 16 receives the detection result of the corresponding number 1 shown in Table 1 described above, the diagnostic unit 16 determines that a small foreign substance exists on the container 3 side as shown in the diagnostic result of Table 1. Then, as shown in the flowchart of FIG. 5, it is determined from the signals from the first sensors 12a and 12b whether the foreign matter is located in a portion where the electric field is high, for example, near the insulating spacer 10 (step 50). . If it is determined that the foreign substance is not located near the high electric field portion, the diagnostic unit 16 takes the action indicated by the reference numeral 52 in FIG. 5, namely, "continues use while strengthening monitoring. The content of "Preparation" is output to the display unit 21. Thereby, the maintenance staff can enhance the coping work according to the content.

Next, if it is determined in step 50 in FIG. 5 that the foreign matter is located near the portion where the electric field is high, the diagnosis section 16
Determines whether the emergency stop of the power device is possible (step 51). As a result, when the power device can be emergency-stopped, the contents indicated by reference numeral 53 in FIG. 5, that is, the content of “Emergency stop, disconnect the relevant part from the system, and inspect the inside” are output to the display unit 21. . The steps described above
In 51, when it is determined that the emergency stop of the power device is impossible, the diagnosis unit 16 shifts to the state indicated by reference numeral 54 in FIG. Separate the part from the system and check the inside. "To the display unit 21.

Next, when the detection results and the diagnosis results shown in the correspondence numbers 2 to 7 shown in Table 1 are obtained, the risk of flashing due to the foreign matter of the power equipment is high, and the diagnosis unit 16 executes the step shown in FIG. At 51, it is determined whether or not an emergency stop of the power equipment is possible,
In response, the contents indicated by reference numerals 53 and 54 in FIG.
Output to 1.

Further, the diagnostic unit 16 can be connected to a trip device that disconnects the unit from the system by a trip command signal.

As described above, according to the embodiment of the present invention, the shape and the location of a foreign object moving in a power device are estimated, the remaining life of the device is predicted from the degree of insulation abnormality caused by the foreign object, and furthermore, Know what to do.

〔The invention's effect〕

According to the present invention, since the shape and existence position of a foreign object moving in a power device are estimated based on a detection signal, the remaining life thereof is predicted, and the degree of danger of the power device is determined. Can take appropriate processing. As a result, reliability and safety can be improved.

Further, according to the method of the present invention, an appropriate treatment policy can be instructed to the maintenance staff in advance, so that the maintenance staff can perform prompt treatment work.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the electric power device of the present invention, FIG. 2 is a diagram showing a specific example of a second sensor used in the present invention, and FIG. FIG. 4 is a characteristic diagram showing the relationship between the length of the foreign matter and the corona generation voltage and the flashover voltage.
FIG. 5 is a characteristic diagram showing the relationship between the length of the foreign substance and the corona generation voltage when the foreign substance is present on the container side, and FIG. 5 is a flow chart for explaining the operation in the present invention. DESCRIPTION OF SYMBOLS 1 ... Gas insulated switchgear, 3 ... Container, 12a, 12b ... 1st sensor, 13 ... 2nd sensor, 14a, 14b, 17 ... Amplifier, 15a, 15b ... Signal processing part, 16 ...... Diagnosis unit, 18 ... Frequency analysis unit, 19 ... Signal comparison unit, 21 ... Display unit.

Continued on the front page (72) Inventor Yosuke Kawada 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Kokubu Plant, Hitachi, Ltd. (72) Inventor Masaru Fukuoka 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture No. 56 Kokubu Plant of Hitachi, Ltd. (56) References JP-A-55-41135 (JP, A) JP-A-55-37868 (JP, A) JP-A-1-313771 (JP, A) 1-287475 (JP, A) Fully open 1987-76675 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 31/00 G01R 31/12 H02B 13/065 H02G 5 / 06 H02H 5/00

Claims (5)

(57) [Claims] 1. A power device having a conductor in a container,
A first sensor for detecting a collision sound of a foreign substance that exists in the container and moves in the container by the action of an electric field and may cause an insulation abnormality to the container, and a partial discharge generated in the container. A second sensor for detecting, and a diagnostic unit for diagnosing a state of the foreign matter in the container, wherein the diagnostic unit determines whether the foreign matter is present on the container side based on a detection signal of the first sensor. And determining the occurrence of partial discharge in the container based on a magnitude comparison result between a detection frequency signal obtained based on a detection signal of the second sensor and a set reference frequency signal, and these determination results A power device for diagnosing a state of a foreign substance in the container based on the power. 2. The power device according to claim 1, wherein the diagnosis unit includes: (1) no foreign matter is present on the container side based on a detection signal of the first sensor, and the detection frequency signal is equal to the reference frequency. When the signal is smaller than the signal, a small foreign substance is attached to the conductor. (2) When the foreign substance is present on the container side based on the detection signal of the first sensor and the detection frequency signal is smaller than the reference frequency signal. A foreign substance having a length exists on the container side. (3) When the foreign substance is present on the container side based on the detection signal of the first sensor and the detection frequency signal is larger than the reference frequency signal A foreign object is floating between the container and the conductor or a large number of foreign objects are present. (4) The foreign object is present on the container side based on the detection signal of the first sensor, and Frequency signal before When the frequency is larger than the reference frequency signal, a foreign substance longer than the foreign substance in the case of (2) exists on the container side. (5) No foreign substance is present on the container side based on the detection signal of the first sensor. If the detected frequency signal is larger than the reference frequency signal, it is diagnosed that a foreign substance longer than the foreign substance in the case (1) exists on the conductor side, and an emergency stop command is output based on the diagnosis result. Power equipment characterized by the following. 3. The power device according to claim 2, further comprising a display unit or an alarm device, wherein the diagnosis result is displayed on the display unit based on an emergency stop command of the diagnosis unit, or an alarm is issued to the alarm device. A power device characterized by causing a 4. A power transmission unit connected to a power system and supported by an insulating spacer, and comprising at least a connection bus bar, a disconnector, a transformer, a circuit breaker, and a lightning arrester connected to the conductor. At least one of the devices includes a first sensor that detects a sound of collision of a foreign object with a container that forms the device, a second sensor that detects a partial discharge generated in the container, A diagnosing unit for diagnosing the state of the foreign matter in the container; and a device for disconnecting the unit from the power system based on a trip command signal output from the diagnosing unit, wherein the diagnosing unit detects a detection signal of the first sensor. And a reference frequency signal set based on the detection frequency signal obtained based on the detection signal of the second sensor. On the basis of the magnitude comparison result to determine the occurrence of a partial discharge in the vessel, and to diagnose the state of foreign matter in the vessel, based on these judgment results,
A power transmission unit that outputs the trip command signal based on the diagnosis result. 5. A power transmission unit connected to a power system and having at least a conductor supported by an insulating spacer, a connection bus bar, a disconnector, a transformer, a circuit breaker, and a lightning arrester connected to the conductor. In the trip method,
A first sensor detects a collision sound of a foreign substance to a container constituting at least one of the devices, detects a partial discharge generated in the container by a second sensor, and generates a detection signal of the first sensor. It is determined whether or not a foreign substance is present on the container side based on the detection result, and the container is determined based on a comparison result of a detection frequency signal obtained based on a detection signal of the second sensor and a set reference frequency signal. The occurrence of partial discharge within the container, diagnose the state of the foreign matter in the container based on the result of the determination, and determine whether the emergency stop of the power transmission unit is possible or impossible based on the result of the diagnosis. If an emergency stop is possible, a trip command signal is output to make an emergency stop of the power transmission unit, and if an emergency stop is not possible, an emergency stop of the power system is performed by system operation. Trip method of power transmission unit, characterized in that disconnecting the power transmission unit from the electric power system shifts to capacity state.