JP2011185396A - Monitoring system of hydraulic operation mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system capable of early detection of abnormality of a hydraulic operation mechanism. <P>SOLUTION: An automatic monitoring device 3 monitors the hydraulic operation mechanism 2 opening/closing a breaker 1 by hydraulic pressure which is maintained by intermittently operating a hydraulic pump 25. The automatic monitoring device 3 includes: a monitoring means 31 monitoring an operating condition (the number of times of starting-up, or operating time), on the basis of an operation signal of the hydraulic pump 25; and a determination means 32 acquiring reference data on past operating conditions, sequentially updating the reference data, and determining whether the hydraulic operation mechanism tends to be abnormal according to a degree of difference between data on the last operating condition and the reference data, after the comparison therebetween. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to a system for monitoring a hydraulic operation mechanism for opening / closing a circuit breaker in a gas insulated switchgear.

  Circuit breakers used in the power system are not opened and closed on a daily basis, but when an accident occurs, it is necessary to immediately disconnect and disconnect the system. Therefore, it is important that the hydraulic operation mechanism that controls opening and closing of the circuit breaker always stands by in a normal state in preparation for the operation. However, since the gas insulated switchgear is housed in the housing including the hydraulic operation mechanism, it is extremely difficult to find an abnormality such as oil leakage from the exterior. Therefore, it is possible to know the leakage of the pipe and the deterioration of the hydraulic pump based on the number of times that the hydraulic pump operated intermittently is started within a predetermined period and the time required for the hydraulic pressure to rise to a predetermined value after starting. A monitoring system is also proposed (see, for example, Patent Document 1).

JP 2008-4413 A

However, in the conventional monitoring system as described above, whether the quality is good or bad is simply determined as compared with a predetermined number of times or time. That is, early detection of abnormalities is difficult.
In view of such conventional problems, an object of the present invention is to provide a monitoring system that can detect an abnormality related to a hydraulic operation mechanism at an early stage.

  The hydraulic operation mechanism monitoring system according to the present invention includes a hydraulic operation mechanism capable of operating an operated portion by hydraulic pressure maintained while intermittently operating the hydraulic pump, and monitoring means for monitoring an operation state based on an operation signal of the hydraulic pump. And reference data on past driving situation is acquired and updated sequentially, and the presence or absence of abnormal tendency is determined according to the degree of difference when comparing the latest driving situation data with the reference data Determination means.

  In the hydraulic operation mechanism monitoring system as described above, the determination means determines whether or not there is an abnormal tendency according to the degree of difference when the data relating to the latest driving situation is compared with the reference data relating to the past driving situation. Can do. That is, if the latest driving situation is normal, the data should be no different from or slightly different from the reference data. On the other hand, a relatively large difference in data is caused by an abnormal tendency (or fear). According to such a relative comparison from the past to the present, a gradual change (trend) that cannot be detected by comparison with a fixed value can be reliably captured. If it can be determined that there is a possibility of an abnormal tendency, the supervisor can detect the abnormality early by performing some kind of alerting or the like.

Further, in the hydraulic operation mechanism monitoring system, the monitoring means and the determination means use the number of times the hydraulic pump is started as the operation status, and the determination means indicates the latest average start number and the average start number obtained before that. You may make it compare.
In this case, the occurrence or progress of oil leakage can be detected early based on the difference between the latest average number of activations and the average number of activations acquired before that.

In the hydraulic operation mechanism monitoring system, the monitoring unit and the determination unit use the operation time after the start of the hydraulic pump as the operation status, and the determination unit compares the newly acquired operation time with the past average value. You may make it do.
In this case, based on the difference between the newly acquired operation time and the past average value, it is possible to detect the occurrence of the hydraulic pump performance deterioration or the occurrence or progress of oil leakage at an early stage.

In addition, in the hydraulic operation mechanism monitoring system, the determination unit includes a determination range in which the hydraulic pump activation count in a predetermined period is equal to or greater than a predetermined value and the operation time after the hydraulic pump activation is within a predetermined range. When deviating from the above, it may be determined that a warning should be issued.
In this case, a clear abnormality can be immediately notified by a warning as well as monitoring a gradual change. That is, when the number of activations is a predetermined value or more, there is a high possibility of oil leakage. Further, when the operation time is equal to or greater than a predetermined range, there is a high possibility that the performance of the hydraulic pump is deteriorated or the oil leaks. When the operation time is equal to or less than the predetermined range, an abnormality of the pressure switch for starting the hydraulic pump is assumed.

  According to the hydraulic operation mechanism monitoring system of the present invention, it is possible to detect a gradual change (trend) related to the hydraulic operation mechanism and detect an abnormality at an early stage.

It is a figure which shows the structure of the hydraulic operation mechanism monitoring system which concerns on one Embodiment of this invention used for a gas insulated switchgear, and has shown the injection state of the circuit breaker. FIG. 2 shows a tripping state of the circuit breaker in the hydraulic operation mechanism monitoring system of FIG. 1. FIG. (A) And (b) is a figure which shows the numerical example regarding the frequency | count of starting, and operation time, respectively. It is a flowchart which shows the process about the frequency | count of starting. It is a flowchart which shows the process about driving time monitoring.

1 and 2 are diagrams showing a configuration of a hydraulic operation mechanism monitoring system according to an embodiment of the present invention used for a gas insulated switchgear, FIG. 1 is a circuit breaker being charged, and FIG. 2 is a circuit breaker. Each tripping state is shown. In the gas insulated switchgear, the main part of the facility including the circuit breaker 1 is housed in a housing (not shown), and SF ₆ gas is enclosed. The circuit breaker 1 is turned on and off by the hydraulic operation mechanism 2. In the drawing, among the two types of hatching indicating the oil liquid in the hydraulic operation mechanism 2, fine hatching represents high-pressure oil, and rough hatching represents low-pressure oil.

  The circuit breaker 1 in FIG. 1 is in a closed state, and the fixed contact 11 and the movable contact 12 are in contact with each other. The hydraulic operation mechanism 2 includes a piston 21 and a cylinder 22 that drive the movable contact 12 of the circuit breaker 1 as an operated portion, an accumulator 23 for holding hydraulic pressure, an oil tank 24, and a hydraulic pump 25 (for driving). The motor and the discharge side include a check valve), the main valve 26 for closing the circuit breaker, and the main valve 27 for tripping the circuit breaker are connected by piping as shown in the figure. The hydraulic operation mechanism 2 includes a drive device 29 for operating the hydraulic pump 25 and the main valves 26 and 27, and a pressure switch 28. The pressure switch 28 detects the hydraulic pressure in the pipe line 20 that always provides a high-pressure hydraulic pressure, and provides it to the drive device 29. In order to operate the main valves 26 and 27, an electromagnetic valve and an amplifying valve which are turned on and off are generally used between the driving device 29, but are omitted here.

  The drive device 29 provides the automatic monitoring device 3 with an operation signal of the hydraulic pump 25 (for example, a contact point contact ON signal of the contactor that drives the hydraulic pump 25). As an internal function, the automatic monitoring device 3 has an monitoring function 31 for monitoring the operation status (number of activations and operation time) based on the operation signal of the hydraulic pump 25 and an abnormality in the hydraulic operation mechanism 2 based on the operation status. And determination means 32 for determining whether or not there is an abnormal tendency. If the automatic monitoring device 3 detects an abnormality or an abnormal tendency as a result of the determination, the automatic monitoring device 3 can provide an output signal to the alarm device 4 to alert or warn. As the alarm device 4, any output form such as display on a display, announcement by sound, lighting of a warning lamp, etc. can be selected. It should be noted that the function of the alarm device 4 can also be incorporated in the automatic monitoring device 3.

  In FIG. 1, the main valve 26 is “open” and the main valve 27 is “closed” by the driving device 29. The high-pressure oil generated by the operation of the hydraulic pump 25 is supplied to the oil chamber 22 a on the piston rod side in the cylinder 22 through the pipe line 20. The high-pressure oil is also supplied to the oil chamber 22 b on the piston head side in the cylinder 22 through the open main valve 26. Here, when a trip command is given to the drive device 29, the drive device 29 switches the main valve 26 to the “closed” state and the main valve 27 to the “open” state, as shown in FIG. When the main valve 27 is opened, the pressure in the oil chamber 22b (FIG. 1) on the piston head side in the cylinder 22 is released and becomes low pressure. Accordingly, the piston 21 is driven in the direction of the arrow in FIG. 2 due to the pressure difference with the oil chamber 22a on the piston rod side, and the circuit breaker 1 is pulled off.

  On the other hand, when an input command is given to the driving device 29 from the tripping state shown in FIG. 2, the driving device 29 “opens” the main valve 26 and opens the main valve 27 as shown in FIG. Switch to the “closed” state. Thereby, the high pressure oil is supplied to the oil chamber 22a on the piston rod side in the cylinder 22 and also supplied to the oil chamber 22b on the piston head side in the cylinder 22 through the open main valve 26. . Accordingly, the piston 21 is driven in the direction of the arrow in FIG. 1 due to the difference in pressure receiving area with respect to the piston 21, and the circuit breaker 1 enters the on state. The high pressure oil is confined within the range shown in the figure, and the hydraulic pressure is held by the accumulator 23.

  The circuit breaker 1 is normally used continuously in the input state. The high pressure oil in the confined state should ideally maintain its hydraulic pressure, but in reality, in FIG. 1, each device (cylinder 22, accumulator 23, hydraulic pump 25, main valve, etc.) constituting the high pressure system. 26, 27), the pipeline 20, and other pipelines (particularly their connection locations), the oil pressure gradually decreases due to slight oil leakage. Therefore, when the hydraulic pressure falls below the allowable lower limit value, this is detected by the pressure switch 28, and the drive device 29 operates the hydraulic pump 25. When the hydraulic pressure increases due to operation and the pressure switch 28 detects a predetermined value, the drive device 29 stops the hydraulic pump 25. The normal operation time is, for example, less than 1 minute, and the normal operation frequency is, for example, less than 10 times a day. That is, the hydraulic pump 25 is operated for a short time and then stopped for a relatively long time, so that the hydraulic pump 25 is intermittently operated, whereby the hydraulic pressure of the high-pressure oil is maintained.

  (A) and (b) of FIG. 3 is a figure which shows the numerical example regarding the frequency | count of starting, and operation time, respectively. As shown in (a), if the number of activations is less than 10 times a day, the high voltage system is normal. On the other hand, when the number of activations is 10 times or more per day, there is a possibility that an oil leak exceeding the normal range has occurred somewhere, and it is necessary to warn to strengthen monitoring. Also, if the number of activations exceeds 20 times a day, it is clearly an abnormal oil leak and there is a risk that the circuit breaker 1 cannot be removed. Don't be.

  Further, as shown in (b), the operation time is normal for less than 60 seconds, but it is abnormal if it is too short, and if it is normal, it should be longer than 10 seconds. Therefore, it is normal that it is longer than 10 seconds and shorter than 60 seconds. It is abnormal for 60 seconds or more, and performance deterioration or failure of the hydraulic pump 25 or oil leakage in the high-pressure system is assumed. On the other hand, if it is 10 seconds or less, a failure of the pressure switch 28 is assumed.

  Next, the operation as the hydraulic operation mechanism monitoring system will be described in detail. The system is mainly composed of a hydraulic operation mechanism 2 and an automatic monitoring device 3 including a monitoring unit 31 and a determination unit 32, and additionally includes an alarm device 4. The automatic monitoring device 3 executes the number-of-starts monitoring and the operation time monitoring shown in FIGS. 4 and 5 in parallel. In the following description of the monitoring operation, it is assumed that the circuit breaker 1 is in the on state.

First, monitoring of the number of activations will be described with reference to the flowchart of FIG.
In FIG. 4, the automatic monitoring device 3 (monitoring unit 31) that has started monitoring the number of activations monitors the operation status based on the operation signal of the hydraulic pump 25. Here, attention is paid to the number of activations as the driving situation. Specifically, the activation of the hydraulic pump 25 from the start of monitoring is integrated by a counter. And every time the number of activations Nd for one day (24 hours) is newly acquired (that is, every time one day elapses), the old data is also stored sequentially. In this way, the automatic monitoring device 3 always stores the data of the number of activations Nd, for example, for two weeks (14 days) while sequentially updating. Then, the automatic monitoring device 3 obtains the average number of activations Nm for the seven days from the current week as “this week” and the average for the previous seven days as “last week”. The number of activations Nmr is obtained (step S11).

  As described above, the automatic monitoring device 3 always counts the number of activations, saves a new Nd value every day, and discards the old Nd value 14 days ago. Also, from that moment, the count of the number of activations per day is newly started. Then, the automatic monitoring device 3 (determination means 32) determines whether or not the average activation number Nm of this week is equal to or greater than the value obtained by adding 1 to the average activation number Nmr of last week when one day has passed (step S12). Is determined (step S13). If the high-voltage system is normal, the average number of activations per day will not be +1 or more (+7 or more per week), and then the automatic monitoring device 3 will determine the number of activations Nd (the latest acquired value) ) Is 10 or more (step S15). As described above, if it is normal, the number of activations Nd per day is less than 10, so in this case, the process returns to step S11 and the same processing is continued.

  On the other hand, in step S13, when the average activation number Nm of this week is equal to or more than the value obtained by adding 1 to the average activation number Nmr of last week, the automatic monitoring device 3 issues a warning instruction to the alarm device 4 (FIG. 1). ) (Step S14). By this alerting, it is possible to inform the monitoring person that an abnormal tendency of increasing the average number of activations is seen and to monitor whether or not the tendency continues. In other words, such determination makes it possible to detect the occurrence and progress of oil leakage and the like at an early stage.

  If alerts continue every day, it is expected that a definite abnormality has progressed, so the supervisor can inspect equipment and pipelines and perform necessary maintenance work at an early stage. it can. Conversely, if there is an alert, but there is no further follow-up, it can be seen that at least no progress has been made, and the supervisor, for example, decides that maintenance work is not required at this stage. can do.

  On the other hand, if the number of daily activations Nd is 10 times or more in step S15, the automatic monitoring device 3 further determines whether or not Nd is 20 times or more (step S16). If 10 ≦ Nd <20, there is a high possibility of oil leakage, so that a warning for the purpose of strengthening monitoring is given by the alarm device 4 (step S17). Further, if “Yes”, that is, if Nd ≧ 20, the oil leakage further progresses and the situation should be referred to as an abnormality of the high-voltage system. Therefore, the automatic monitoring device 3 gives a danger notice that means an abnormality of the high-voltage system. Then, it is performed by the alarm device 4 (step S18). When step S17 or S18 is executed, the automatic monitoring device 3 does not automatically return to step S11, but temporarily ends the monitoring operation.

In the example of the above flowchart, starting from an arbitrary “today”, “this week” is from one week before to today, and “last week” is the previous week, but “this week” and “last week” are the days of the week. May be defined. In this case, the average number of activations per week is acquired on a specific day of the week.
Further, the unit period of one week is an example, and the unit period can be changed as necessary. The same applies to the point of obtaining the average number of activations by a numerical value per day (24 hours), and the number of times of activation per other period (time) may be obtained.

Next, the operation time monitoring will be described with reference to the flowchart of FIG.
In FIG. 5, the automatic monitoring device 3 (monitoring means 31) that has started the operation time monitoring monitors the operation status based on the operation signal of the hydraulic pump 25. Here, attention is focused on the operation time after startup as the operation status. Specifically, in step S21, the operation time T from the start to the stop of the hydraulic pump 25 is measured by a timer. Then, every time the data of the operation time T is newly acquired (that is, every time of starting / stopping), the average value with the past data, that is, the average operation time Tm is measured (step S21). The past data may be limited to the most recent predetermined number, or may be all data after the start of monitoring. In any case, the average operation time Tm is sequentially updated every time data of the operation time T is newly acquired.

  As described above, the automatic monitoring device 3 updates the average operation time Tm every time the operation time T is newly measured. Then, when the automatic monitoring device 3 (determination means 32) newly measures the operation time (step S22), whether the operation time T is equal to or greater than the value obtained by adding 10 [seconds] to the average operation time Tm. It is determined whether or not (step S23). If the hydraulic pump 25 is normal, the operation time T will not be longer than the average operation time Tm by 10 seconds or more, and then the automatic monitoring device 3 determines whether or not the operation time T is 60 seconds or more. (Step S25) Further, it is determined whether or not the operation time T is 10 seconds or less (Step S26). As described above, if it is normal, the operation time T [second] is 10 <T <60. In this case, the process returns to step S21 and the same processing is performed.

  On the other hand, if the operation time T is longer than the average operation time Tm by 10 seconds or more in step S23, the automatic monitoring device 3 gives a warning instruction to the alarm device 4 (FIG. 1) (step S24). This alerting alerts the supervisor that an abnormal trend of increased driving time is seen, and can monitor whether the trend continues. That is, by such a determination, it is possible to find out early the occurrence or progress of the hydraulic pump performance degradation or oil leakage.

  If alerting continues every time the operation stops, it is expected that a definite abnormality has progressed. Therefore, the supervisor mainly inspects the hydraulic pump 25 and performs necessary maintenance work at an early stage. Can be done. Conversely, if there is an alert, but there is no further follow-up, it can be seen that at least no progress has been made, and the supervisor, for example, decides that maintenance work is not required at this stage. can do.

  On the other hand, if the operation time T is 60 seconds or longer in step S25, there is a high possibility that the performance of the hydraulic pump 25 is reduced or oil leaks. Accordingly, the automatic monitoring device 3 causes the warning device 4 to issue a warning for prompting the inspection of the equipment and the pipeline (step S28). In step S26, if the operation time T is 10 seconds or less, an abnormality of the pressure switch 28 that activates the hydraulic pump 25 is assumed. Therefore, the automatic monitoring device 3 causes the warning device 4 to give a warning notifying the abnormality of the pressure switch 28 (step S27). When step S27 or S28 is executed, the automatic monitoring device 3 does not automatically return to step S21, but temporarily ends the monitoring operation.

  It should be noted that when the hydraulic operation mechanism 2 is first started, the hydraulic pump 25 is operated from a state where the hydraulic pressure is zero, so that a considerably long operation time is required. For example, normally, when the hydraulic pressure of the high-pressure oil becomes lower than 32 MPa, the hydraulic pump 25 is activated, and it takes about 25 seconds until the hydraulic pressure is increased to 34 MPa and stopped. In contrast, it takes about 7 minutes for the hydraulic pump 25 to increase the hydraulic pressure from 0 MPa to 34 MPa. Therefore, it is preferable that the operation time at the time of the first start is excluded from the measurement of the operation time.

  As described above, according to the hydraulic operation mechanism monitoring system according to the present embodiment, when the determination unit 32 compares the data related to the latest driving situation (starting count / driving time) with the reference data related to the past driving situation. The presence or absence of an abnormal tendency can be determined according to the degree of difference. That is, if the latest driving situation is normal, the data should be no different from or slightly different from the reference data. On the other hand, a relatively large difference in data is caused by an abnormal tendency (or fear). According to such a relative comparison from the past to the present, a gradual change (trend) that cannot be detected by comparison with a fixed value can be reliably captured. By alerting based on such determination, the supervisor can detect the abnormality early.

  Further, in the hydraulic operation mechanism monitoring system, the determination unit 32 determines that the operation time T after the hydraulic pump 25 is activated when the hydraulic pump 25 activation frequency Nd is greater than or equal to a predetermined value during a predetermined period (one day). When it deviates from the predetermined range (10 seconds <T <60 seconds), it is determined that a warning should be given. Therefore, an obvious abnormality can be immediately notified by a warning as well as monitoring a gradual change. .

In the above-described embodiment, monitoring is performed from both the number of activations and the operation time, but only one of the monitoring may be performed. However, it is difficult to detect the performance deterioration of the hydraulic pump from the number of start-ups. Therefore, it is preferable to use the operation time monitoring together.
Moreover, although the said embodiment was set as the hydraulic operation mechanism for operating the circuit breaker (contact point) in a gas insulated switchgear as an example, object is not necessarily limited to such a circuit breaker. In short, the same system can be applied as long as it is an operation mechanism that maintains the hydraulic pressure and waits while intermittently operating the hydraulic pump so that the operated part can be operated.

DESCRIPTION OF SYMBOLS 1 Circuit breaker 2 Hydraulic operating mechanism 3 Automatic monitoring device 25 Hydraulic pump 31 Monitoring means 32 Determination means

Claims (4)

A hydraulic operating mechanism capable of operating the operated part by the hydraulic pressure maintained while intermittently operating the hydraulic pump;
Monitoring means for monitoring the operation status based on the operation signal of the hydraulic pump;
Judgment to determine whether there is an abnormal trend according to the degree of difference when reference data related to past driving conditions is acquired and updated sequentially and the latest driving condition data is compared with the reference data And a hydraulic operating mechanism monitoring system.   The monitoring unit and the determination unit use the number of times of activation of the hydraulic pump as the operation state, and the determination unit compares the latest average number of times of activation with the average number of times of activation acquired before that. Hydraulic operating mechanism monitoring system.   The monitoring unit and the determination unit use an operation time after starting the hydraulic pump as the operation state, and the determination unit compares the newly acquired operation time with a past average value. The hydraulic operating mechanism monitoring system described in 1.   In addition to the determination, the determination means gives a warning when the number of activations of the hydraulic pump in a predetermined period is greater than or equal to a predetermined value and when the operation time after the activation of the hydraulic pump deviates from a predetermined range. The hydraulic operation mechanism monitoring system according to any one of claims 1 to 3, wherein a determination is made that the operation should be performed.

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