JPH01214219A - Diagnostic method for substation machinery - Google Patents

Abstract

PURPOSE:To simplify the system and to improve the reliability of diagnosis, by selecting sampling signals synchronized with the system voltage from the secondary voltage of a common potential transformer based on judgement criteria such as the soundness, and feeding the sampling signals to individual diagnostic units. CONSTITUTION:Secondary voltage of a potential transformer is taken into the system voltage input circuit 22 in a monitor 6 in the form of V1, V2 and converted into preferable level. A voltage detection circuit 21 judges the soundness of system voltage based on the converted signal. A logical judgement section 20 makes a judgement based on the judgement result of the voltage detection circuit 21 and information fed from an l/O circuit 19, and provides a selection signal to a voltage signal selection circuit 18. A synchronous signal generating circuit 17 receives a selected voltage signal VS and produces a sampling signal SY synchronized with the system voltage signal, and a synchronous signal transmitting section 16 provides the synchronous signal SY to a diagnostic unit 1.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a preventive diagnosis method for substation equipment such as gas-insulated switchgear, and in particular, a substation suitable for detecting abnormal phenomena with high accuracy. Concerning preventive diagnostic methods for equipment.

[Conventional technology]

As a prior art related to a preventive diagnosis method for substation equipment, for example, gas insulated switchgear, for example, Japanese Patent Application Laid-Open No. 144765
The mental technology is known as described in the No. 1 publication. In this conventional technology, a secondary output of a voltage transformer connected to the grid is given to a diagnostic device provided corresponding to each of a plurality of gas-insulated switchgears, and a signal generated by an AC it voltage VCIv1 is used to When one cycle of AC voltage is divided into appropriate time periods, abnormalities and their causes are detected based on the abnormality detection result pattern for each time period. Hereinafter, the diagnostic method according to the prior art will be explained with reference to the drawings.

FIG. 4 is a diagram of a standard electrical plant equipped with a diagnostic method according to the prior art. In Fig. 4, 1 is a gas insulated switchgear, 2 is a voltage transformer, 3 is a circuit breaker, 4 is a disconnector, and 5 is a
6 is a diagnostic device, 6 is a monitoring device, and 7 is a signal cable.

When a general electric station is configured with gas-insulated switchgear and the like, a plurality of such devices are required, and a plurality of corresponding diagnostic devices are also usually required.

The electrical station illustrated in FIG. 4 includes two busbars, a plurality of gas-insulated switchgear 1 that connects one of these busbars to other equipment, or connects the busbars to each other, and these gas-insulated switchgears. A diagnostic device 15 provided corresponding to the device IK,
A voltage transformer 2 connected to each bus bar and supplying its secondary voltage to each of the diagnostic devices 5; and a monitoring device 6 that receives the diagnosis results of the gas-insulated switchgear fill by each diagnostic device 5 via a signal cable 7. It is made up of. Further, each gas insulated switchgear 1 includes a plurality of disconnectors 4 and circuit breakers 3.

In Fig. 4, one voltage transformer 2 is generally installed on each bus bar from the viewpoint of equipment downsizing and economical efficiency, and its secondary output is usually located at one location in the electrical station. Commonly used for various protection and control devices installed centrally. The diagnostic device 5 is attached to the main body of the gas insulated switchgear 1 in order to detect an abnormality in the gas insulated switchgear 1, and the output signal of the abnormality detection sensor is a micro urinal.
They are installed in the vicinity of the main body of each insulated switchgear l, that is, distributed outdoors, and the detection signal is sent via the monitoring device ff161c installed in the monitoring and control room, etc., and the signal cable 7, and the abnormality is detected. Inform the driver.

[Problem that the invention attempts to solve]

In the prior art, it is necessary to take sufficient measures to prevent rounding, surges, noise, etc. when the diagnostic equipment 5 is distributed outdoors, and for example, consideration must be given to configuring the signal line 7 with an optical cable or the like. . However, in this prior art, the secondary output of the voltage transformer 2, which is shared with protection and control devices directly related to the supply of electric power, is directly supplied to the diagnostic equipment 5 installed outdoors. This poses a problem in that the required length of the electric cable increases, reducing the reliability of protection, control equipment, etc.

9. In order to avoid such problems, the voltage signal is converted into an optical signal and is configured to be supplied to the diagnostic device 5. Even in the following case, this configuration does not require that the voltage signal be converted to an optical signal and supplied to the diagnostic device 5. As in the case of supply, each of the diagnostic devices 5 must individually determine and select which voltage transformer to use as a voltage signal, which poses the problem of complicating the diagnostic device 5. cannot be resolved.

(9) In the conventional technology, an abnormality diagnosis is performed for each gas-insulated switchgear, and in such cases, it is difficult to distinguish abnormalities other than the target gas-insulated switchgear, such as abnormal discharges in power transmission lines, from abnormalities in the gas-insulated switchgear. This poses a problem in that diagnostic accuracy is lowered, such as erroneous diagnosis in which an abnormal phenomenon in a power transmission line is mistakenly determined to be an abnormality in a gas-insulated switchgear.

The purpose of the present invention is to solve the problems of the prior art described above,
The object of the present invention is to provide a preventive diagnosis method for substation equipment that simplifies the system and improves the reliability of diagnosis.

[Next means to solve the problem]

According to the present invention, the purpose is to transmit a sampling signal to a plurality of diagnostic devices in synchronization with the voltage of a system selected from the secondary voltage of a commonly provided voltage transformer based on the criterion sK for determining the health of the transformer. This can be achieved by making it commonly used.

[For production]

The system can be simplified by selecting a sampling signal synchronized with the grid voltage from the secondary voltage of a commonly installed voltage transformer based on criteria such as its health, and supplying it to each diagnostic equipment. It is possible to aim for

In addition, since the diagnostic conditions for multiple gas-insulated switchgears are the same due to the common use of sampling signals, by comparing and determining the diagnostic result information of multiple diagnostic devices, it is possible to diagnose individual gases with highly reliable waves. It becomes possible to diagnose insulated switchgear.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the preventive diagnosis method for substation equipment according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a preventive diagnostic device including a diagnostic device and a monitoring device that implement the method of the present invention, and FIG.
FIG. 3 is a waveform diagram illustrating the operation of FIG. 1. In FIG. 1, 8 is a sensor, 9 is a discharge light detection section, 10 is a discharge pulse detection section, 11 is a logic judgment section, 12 is a diagnostic result output section, 13 is a synchronization signal reception section, and 14 is a control signal 15 is an input section, 16 is a synchronization signal transmission section, 17 is a synchronization signal generation circuit, 18 is a voltage signal selection circuit, 19 is an input/output circuit, 21 is a voltage detection circuit, n is a system voltage input circuit, Other symbols are the same as in FIG. 4.

The embodiment of the present invention shown in FIG. 1 detects an abnormal internal discharge in a gas insulated switchgear 1 using a discharge current detection sensor inserted between the case of the main body and the ground. An example of diagnosis is shown.

In FIG. 1, a plurality of gas insulated switchgear 1 are provided depending on the configuration of electrical equipment, and a diagnostic device 5 and a sensor 8 are also provided corresponding to each gas insulated switchgear 10.

In FIG. 1, only one of these is shown for ease of explanation. When a plurality of diagnostic devices 5 are provided,
The diagnostic device 5 is individually connected to each of the several connection boats provided in the monitoring device 6.

The diagnostic device 5 includes a discharge light detection section 9 and a discharge pulse detection section 1.
The monitoring device 6 includes an input section 15, a synchronization signal reception section 16, a synchronization signal generation circuit 17, a voltage Signal selection circuit 18, input/output circuit 19
, a logic judgment circuit, a voltage detection circuit 21, and a system voltage input circuit B.

The monitoring device 6 is commonly installed indoors in a monitoring, control room, etc. for a plurality of diagnostic devices 5, and is configured to include a plurality of input units 15 when connecting to a plurality of diagnostic devices 5.

Next, its operation will be explained.

When the present invention is applied to an electrical station configured similarly to that shown in FIG. 4, the secondary voltage of the nine voltage transformers 2 shown in FIG. . This level-converted output is sent to the voltage detection circuit 2.
1, and the voltage detection circuit 21 determines the health of the grid voltage, for example, whether the magnitude of the voltage is a steady value, based on this signal. The logic judgment section determines that there is no abnormality such as a voltage drop based on the judgment result of the voltage detection circuit 21, and that there is no abnormality such as voltage drop or the like, and that the gas insulated switchgear [1] is turned on or off. From the information, it is determined which bus side the gas insulated switchgear 1 to be diagnosed is connected to, and based on the results of these determinations, a selection signal is issued to the voltage signal selection circuit 18, making it the target for diagnosis. A voltage signal system most suitable for use as a sampling synchronization signal is selected for the diagnostic device 5 of the gas-insulated switchgear 1. The synchronization signal generation circuit 17 receives the voltage signal S selected above and generates a nine-sampling synchronization signal SA in synchronization with the voltage signal of this system. The synchronization signal transmitter 16 supplies the sampling synchronization signal S to the diagnostic device 1 to be diagnosed, and for example, the sampling synchronization signal S,
is converted into an optical signal etc. and sent out.

FIG. 2 shows waveforms of the two system voltage signals V, , V, the voltage signal vs selected by the voltage selection circuit 18, and the sampling synchronization signal Sy. In Fig. 2, the level at which it is determined whether the grid voltage is healthy or not is shown as voltage level VD. In the example shown in this figure, the grid voltage signal V exceeds level VD, and the grid voltage Since the signal v2 is smaller than the level VD, the voltage selection circuit 18 selects the nine voltage signal vs, which is vl, as the sampling synchronization signal S.

indicates that it is synchronized with the grid voltage on the v1 side.

On the other hand, in the diagnostic device 5, the ground current detected by the sensor 8 connected to the case of the main body of the gas insulated switchgear 1 is removed by the discharge current detection unit 9, which removes signals unnecessary for diagnosis such as commercial frequency components. and only the discharge current component is detected. The discharge detection signal detected by the discharge flow detection section 9 is detected by discharge pulse detection based on the sampling signal SPK created by the synchronization signal reception section 13 which receives the sampling synchronization signal Sy mentioned above and the control signal generation section 14. From this sample K, the presence or absence of discharge is detected at every sampling interval synchronized with the system voltage signal.

The logic determining unit 11 determines the discharge pattern for each sampling interval synchronized with the grid voltage signal based on the detected discharge pulse signal lp from the discharge pulse detecting unit 10 in response to the determination activation signal OP from the control signal generating unit 14. , to examine the presence or absence of abnormalities and their causes. In this way, the next medical examination IT
The results are converted into an optical signal or the like by the diagnosis result output section 12 and sent to the input section 15 of the supervisory control device 60, and then displayed on a display device or the like via the logic judgment section and turnout circuit 19. to notify maintenance personnel of the abnormality.

The operation of the diagnostic device 5 described above is shown in a waveform diagram in FIG. In the example shown in FIG. 3, one cycle of the voltage waveform V applied to the gas-insulated switchgear 1 is equally divided into 12, and the sampling pulse SP synchronized with the time period is used to detect nine cycles by the discharge current detection unit 9. This figure shows how the discharge pulse detection section 10 detects the discharge current ig and outputs it as a detected discharge pulse signal 1p.

The judgment in the logical judgment unit 11 is performed, for example, as follows. That is, for example, if a discharge pulse is detected during periods I and J in FIG. If it is determined that there is a possibility of a sharp edge part occurring in the gas in the bag [1], and if discharge pulses are detected randomly without depending on the voltage phase trap, it may be due to poor contact of metal parts, etc. It can be determined that this may be due to the cause.

Next, a description will be given of the judgment operation of the logic judgment unit 20 in the monitoring device 6, such as when issuing a diagnosis result based on the above-mentioned operation busyness as an alarm signal to the operation and maintenance personnel of the electrical plant.

If the diagnosis result taken in through the diagnosis result output section 12 of the diagnosis device 5 and the input section 15 of the monitoring device 6 is determined to be abnormal, the logic judgment section adds a plurality of other identical samplings. Check whether the diagnostic devices using the information are detecting the same pattern of discharge pulses and reporting an abnormality, and check whether multiple diagnostic devices are detecting the same pattern of discharge pulses and reporting an abnormality. In some cases, it is not determined that it is a final abnormality, and therefore the system operates so as not to issue an alarm. This is a phenomenon that occurs when there is an abnormality in something other than the gas insulated switch, for example, a power transmission line, and it can be determined that there is no abnormality in the gas insulated switch 1 itself. Also,
At the same time as receiving the abnormality determination report from the diagnostic device 5, the logic judgment unit also performs this process when the detection result from the voltage detection circuit 21 indicates that the grid voltage has lost its integrity. It will not be judged as abnormal and will not issue an alarm signal. This is because in this case, an accident may occur due to a lightning strike to the grid.

In the embodiment of the present invention, by making the above-described judgment in the logical judgment section, it is possible to prevent erroneous diagnosis and improve the reliability of diagnosis.

In the embodiments of the present invention described above, the present invention is applied to preventive diagnosis of gas-insulated switchgear.
It can be applied for preventive diagnosis of other substation equipment such as transformers and arresters.

By the way, in the embodiment of the present invention described above, the connection between the monitoring device 6 and the plurality of diagnostic devices is 1:n! It is sufficient if it is done in any form, such as & continuation, connection by loop transmission line, etc.
The monitoring device 6 may use a 4N method that allows identification of individual diagnostic devices.

According to this embodiment of the present invention, sampling signals synchronized with the grid voltage supplied to each diagnostic device are commonly provided and selected from the voltage transformers, so that the overall system The configuration can be simplified, and the sampling synchronization signal is selected and the final judgment is made depending on whether the grid voltage is healthy or not, so the reliability of diagnosis can be improved, and it can be used in common with multiple diagnostic devices. By using the sampling synchronization signal, it is possible to make a comprehensive judgment, so it is possible to prevent incorrect diagnosis due to abnormalities in equipment other than the target or system failures, etc., and furthermore, it is possible to improve the reliability of diagnosis. Can be done.

〔Effect of the invention〕

As explained above) According to the present invention, it is possible to simplify the system and increase the reliability of diagnosis, and it has the effect of improving economical efficiency and reliability of power supply.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a preventive diagnostic device including a diagnostic device and a monitoring device that implement the method of the present invention, FIGS. 2 and 3 are waveform diagrams explaining the operation of FIG. 1, and FIG. 1 is an equipment configuration diagram of an FC standard electrical station equipped with a diagnostic method according to the prior art; FIG. 1... Gas insulated switchgear, 2... Voltage transformer, 3... Circuit breaker, 4... Disconnector, 5... Diagnostic device, 6...Monitoring device,
7...Signal cable, 8...Sensor,
9...Discharge current detection unit, lO...Discharge pulse detection unit, 11.20...Logic judgment unit, 1
2...Diagnosis result output section, 13...Synchronization signal generation circuit, 14...Control signal generation section, 15
...Input section, 16...Synchronization signal transmission section, 17...Synchronization signal generation circuit, 18...
・Voltage signal selection circuit, 19... Input/output circuit, 2
1... A, pressure detection circuit, n... System voltage input circuit. Agent Patent Attorney Takeshi Junji Department (1 other person) Figure 2? 1￥ Figure 3 Figure 4/・t's&! j&I51! To RK 2-tFLt:

Claims (1)

[Scope of Claims] 1. A preventive diagnostic device comprising a plurality of diagnostic devices for detecting abnormalities in substation equipment and one monitoring device connected to each of the plurality of diagnostic devices, wherein the monitoring device 1. A preventive diagnosis method for substation equipment, characterized in that a synchronization signal for a sampling signal synchronized with voltage and used by the diagnostic device to detect an abnormality in the equipment is distributed to each of the plurality of diagnostic devices as a common synchronization signal. 2. The preventive diagnosis method for substation equipment according to claim 1, wherein the system voltage is selected by the monitoring device as a healthy system voltage from a plurality of given system voltages. 3. The monitoring device detects when the system voltage is not healthy;
3. A preventive diagnostic method for power substation equipment according to claim 1 or 2, characterized in that the diagnostic operation is stopped. 4. The preventive diagnostic method for substation equipment according to claim 1, 2, or 3, wherein the monitoring device comprehensively judges diagnostic information from the plurality of diagnostic devices. . 5. The method according to claim 1, 2, 3, or 4, wherein the plurality of diagnostic devices and one monitoring device are interconnected by optical signals. Preventive diagnosis method for substation equipment.