JPH02213105A - Operation monitoring apparatus for on-load tap changer - Google Patents

Abstract

PURPOSE:To provide a system which makes it possible to monitor the overall operation of an on-load tap changer by providing a detecting means having at least one of a pressure detecting part which detects the change in pressure in a switch, an operation-part-strain detecting part and a transmission-strain detecting part, and providing a monitoring means which monitors the operating state based on the detected signal from the detecting means. CONSTITUTION:An operation body 6 is driven and operated by a driving force which is transmitted through a transmission 10. Tap change is performed with a switch DS. An operation monitoring system of an on-load tap changer LTC having said switch DS is provided with a detecting means and a monitoring means which monitors the operating state based on the detected signal of said detecting means. The detecting means has at least one of the following three parts : a pressure detecting part S1 which detects the change in pressure in said switch DS; an operation-body-strain detecting part which detects the strain generated in said operating body 6; or a transmission-strain detecting part S3 which detects the strain generated in said transmission 10. For example, said monitoring means is a processor PU comprising an input circuit 20, an operating circuit 30, a judging circuit 4 and a display circuit 50.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an operation monitoring system for an on-load tap changer.

[Conventional Technique 1] On-load tap changers have been indispensable for power flow control of power system voltage and phase, and have been used in transformers for a long time, and in recent years, their production and operation results have increased dramatically. It has been steadily increasing.

In addition, as one of the few mechanical parts of a transformer,
As earthenware vessels that carry the main circuit current, their reliability is increasing year by year, and the demand for even higher reliability is likely to increase in the future.

In addition, various protection devices have been proposed and adopted so far as part of the protection of tap changers under load, in order to detect internal abnormalities that occur due to some cause. - An example is as shown in FIG.

FIG. 5 shows a conventional example of the configuration of an on-load tap changer and the equipment of a protection device. This kind of thing was published in Japanese Patent Application Publication No. 4
．． 7-10719, Utility Model Publication No. 63-3131, etc., and is disclosed in - Boat fishing.

This conventional device will be explained with reference to FIG.

In the figure, LTC is a load tap changer, DS is a switching switch equipped with a contact part 5 for current switching, and TS is a tap selector that selects and connects the tap of the tap winding.

In the switching switch DS, the internal insulating oil 7 and the transformer internal insulating oil 8 are completely separated by a suitable cylindrical insulator 4, and the internal and external insulating oils 7°8 are prevented from mixing. Moreover, the switching switch DS is attached so as to be suspended from the transformer tank cover 11 into the transformer tank 1. The tap selector TS is attached to the lower part of the switching switch DS. Further, the head 9 of the switching switch DS is exposed outside the transformer tank 1, and is connected via horizontal and vertical transmission shafts 10 to the conduction operating device l! which is the drive source for changing the taps. Connected to DM.

Moreover, 12 and 13 are oil guide pipes on the inlet side and the outlet side that connect the head 9 of the switching switch DS and the live oil purifier 15, respectively. Inside the live line oil purifier 15, the oil guide pipe 12.
A filter medium 14 is provided through which oil passes. Oil contaminated by oil decomposition due to arc generated during tap switching is circulated and purified through the filter medium 14a.

On the other hand, 16 is an oil flow relay as a protection device;
7 is a pressure relief device.

Here, in order to proceed with the explanation from the viewpoint of protection, it is assumed that some serious abnormality occurs inside the switching switch DS, for example, an arc abnormally extends during switching, and a short circuit between taps occurs.

When a short circuit occurs between the taps, a large current flows and the arc continues, causing the movable and fixed contacts 71 and 71 shown in FIG.
72. In addition, it not only causes overheating and melting of insulators, etc.
The rapid decomposition of oil generates a large amount of gas, causing a sharp rise in internal pressure and oil flow. If this is left as it is, the cylindrical insulator 4 of the switching switch DS will not be able to withstand the rising pressure and will be destroyed, resulting in a fatal blow to the inside of the transformer.

[Problem to be solved by the invention] In order to prevent this, the oil flow relay 16 is provided.
and a pressure relief device [17]. these are.

It operates during the development of the above phenomenon, and has the role of stopping the transformer before a serious accident occurs.

These are from the point of preventing fatal injuries.

This is an essential device. However, from the viewpoint of preventive maintenance, which is to prevent accidents from occurring, it must be said that this is insufficient. - When an accident occurs, it takes time and money to take measures that are completely unplanned, which reduces the economic efficiency of the equipment. There is also room for improvement in terms of operational management.

By the way, regarding transformer accidents caused by equipment malfunctions,
Electric Kyodo Research Vol. 35 No. 4 “Standardization of load tap changer transformers for power distribution” (October 1973);
It is statistically summarized in Volume 1, Issue 5, ``Measures to improve the reliability of substation equipment'' (February 1986). According to the report, the percentage of accidents related to on-load tap changers in transformer accidents varies slightly depending on the statistical period, but in the highest case, it accounts for nearly half of the total number, and among them, the number of accidents related to on-load tap changers is Approximately 65% of the respondents were related to

These problems are due to the fact that it has traditionally been impossible to predict appropriate signs of abnormality in advance, and there has been no system for this purpose. Therefore, if malfunctions related to the switching switch and the drive system such as the transmission body can be predicted in advance, accidents with the on-load tap changer can be prevented.

In view of the above points, the present invention captures various abnormal phenomena that occur in the drive system such as the switching switch and the transmission body when changing the tap, and compares and determines them with normal values. The purpose of this invention is to provide a system that enables a comprehensive view of driving.

[Means for Solving the Problems] The present invention provides a driving force transmitted through a transmission body.
In an on-load tap changer that has a switching switch that performs a tap change operation by driving an operating body, extracts a signal representing the operating state of the target on-load tap changer and monitors the state. Provides a driving monitoring system.

In addition, in this type of on-load tap changer, a transmission shaft is used as the transmission body. Since an operating shaft is used as the operating body, the following description will be made using the terms transmission shaft and operating shaft. However, the present invention is not limited to this.

As shown in FIG. 1A, the operation monitoring system of the present invention includes a pressure detection section that detects a change in the internal pressure of the switching switch, and a strain that occurs on the operation shaft as a means for extracting a signal representing the operating state. an operating axis distortion detection unit that detects
The transmission shaft is configured to include a detection means having at least one of the transmission shaft strain detection parts that detect strain occurring in the transmission shaft, and a monitoring means that monitors the operating state based on a detection signal of the detection means. Ru.

The detection means detects a pressure change due to gas produced when insulating oil is decomposed by an arc during tap switching, a strain produced on the operating shaft of the switching switch during tap switching, and/or a drive force on the operating shaft during tap switching. Detects the strain that occurs in the power transmission shaft that transmits force. The monitoring means compares these detection results with normal changes to monitor abnormalities during tap switching.

The detection means may include all of a pressure detection section, an operation shaft strain detection section, and a transmission shaft strain detection section.

Further, in the case of an on-load tap changer equipped with a live line oil purifier that purifies insulating oil in the switching switch, the detection means includes an oil contamination level detection section that detects the degree of contamination of the insulating oil. Preferably, means are provided.

Further, the present invention can also be configured to include a detection means having a current detection section that detects the current at the time of tap switching of the tap winding. In this case, the monitoring means is provided with a function of calculating the amount of wear of the contacts of the switching switch based on the detected current value, and monitoring the wear of the contacts based on the calculation result.

Although this current detecting section can be provided as an independent detecting means, it is preferable to provide it together with the pressure detecting section, etc. Accordingly, as a monitoring means.

Based on the current value detected by the current detection section, the amount of wear of the contact of the switching switch is calculated and the wear of the contact is monitored, and if there is an abnormality in the pressure detected by the pressure detection section. In addition, it is preferable to have a function of determining the relationship between wear and tear of the contactor.

The driving monitoring system of the present invention is based on a signal representing the state of an object detected by a sensor.

For the condition, at least one type of data is obtained from among the peak value, duration, integral value, average value, cumulative value, and change pattern, and this data is compared with set criteria to determine whether there is an abnormality. Judge.

The determination result is output.

As shown in FIG. 1B, a monitoring device suitable for such monitoring calculates the peak value, duration, integral value, and average value of the state of the object based on a signal representing the state of the object detected by the sensor. , a calculation means for calculating at least one type of data among the cumulative value and the change pattern, a determination means for comparing this data with a set determination criterion to determine the presence or absence of an abnormality, and outputting the determination result. and output means.

In this case, the determining means determines the presence or absence of an abnormality, and
It is preferable to have a function of determining that the system is normal if there is no abnormality in any of the plurality of determination results, and determining that the system is abnormal if any of the determination results is abnormal.

[Operation] Each of the detection sections constituting the detection means of the present invention operates as follows in conjunction with the monitoring means. First, it is possible to monitor pressure changes based on the detected value of the pressure detection unit in the switching switch and find signs of abnormality during switching.

On the other hand, by detecting changes in strain using a strain detection section provided on the operation shaft of the switching switch, it is possible to determine whether the switching switch is stopped midway or if there is a short circuit between taps.

Furthermore, by detecting a change in the value of the strain detection section of the transmission shaft, it can be determined that there is a sign of abnormality in the N dynamic system.

Furthermore, if the live-line oil purifier is controlled to operate continuously until the detection value of the insulating oil contamination level detection unit installed in the inlet side oil pipe of the live-line oil purifier reaches a certain specified detection sensitivity, the insulation will decrease. Accidents caused by such problems will be prevented.

Furthermore, the amount of wear of the switching switch contactor during tap switching is calculated based on the current value detected by the current detection means of the tap winding, and the result is incorporated into the detection result to increase the reliability of the determination result. Can be done.

In other words, by making appropriate judgments using the multifaceted data detected, it is possible to build a comprehensive operation monitoring system that can detect signs of abnormalities in advance, and promote planned shutdowns of transformers and periodic inspections. , appropriate measures can be taken that do not interfere with the operation of the equipment.

Of course, an operation monitoring system can be constructed, albeit partially, by the individual detection means and monitoring means.

(The following is a blank space) [Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2A shows the configuration of an embodiment of the on-load tap changer operation monitoring system of the present invention.

In FIG. 2, the on-load tap changer LTC to which this embodiment is applied includes a changeover switch DS equipped with a contact part 5 for current switching, and a tap selector for selecting and connecting the taps of the tap winding. It is composed of a TS, these quick-action systems, etc. Basically, it has the same configuration as the on-load tap changer LTC shown in FIG. 5 described above. Therefore, the same parts will be given the same reference numerals and the description will not be repeated.

The on-load tap changer LTC of this embodiment differs from the conventional one described above in that it includes a sensor section constituting a detection means.

That is, the pressure detection section S1 inside the switching switch DS is provided on the upper surface of the mechanism section 9 of the switching switch DS, and
The operating shaft distortion detection section S2 of the operating shaft 6 is provided on the operating shaft 6 close to the mechanism section 9 side.

A transmission shaft strain detection section S3 is provided on the transmission shaft 10 close to the electric operating mechanism DM.

The pressure detection section S1 may be provided on a portion other than the upper surface of the mechanism section 9, for example, on a side surface.

Switch open/close! It can be provided at any position where the pressure inside ID5 is transmitted.

Further, the operation shaft strain detection section S2 may be located within one mechanism section 9, and similarly, the transmission shaft strain detection section S3 may be located on the transmission shaft on the mechanism section 9 side, that is, at any position where each strain occurs. An appropriate location can be selected taking into account ease of inspection.

The pressure detection section 81 described above. The operating shaft strain detecting section S2 and the transmission shaft strain detecting section S3 are not limited to one location, but the same detecting section may be arranged at multiple locations.For example, the pressure detecting section S1 is a detecting section 1 with the same detection content. It is preferable to set a plurality of values because the Ws fixed difference can be reduced.

By arranging these at a plurality of locations, measurement errors can be reduced, and the distribution of strain generation can also be detected, which has the advantage of being able to detect fatigue of the shaft body.

Note that pressure detection and strain detection can be performed not only on the above-mentioned object but also on other members.

Here, for these pressure detecting section 51, switching switch operation shaft strain detecting section S2, and transmission shaft strain detecting section S3, sensors with good followability and high reliability, such as strain gauges, are used. A method is used to detect signals based on changes in the resistance of the gauge. However, pressure.

Other sensors capable of detecting distortion or the like may also be used.

Next, an example of the monitoring means constituting this embodiment will be explained.

As shown in FIG. 2A, the monitoring means of this embodiment is as shown in FIG.

The processing unit PU includes an input circuit 20, an arithmetic circuit 30, a determination circuit 40, and a display circuit 50.

This processing device 1PU can be configured by, for example, hardware as shown in FIG. 2E.

That is, a CPU 90 that executes control, calculation, judgment, etc. of the entire monitoring system, a ROM 91 that stores the operating program of the CPU 90, and a RAM 92 that stores various setting reference values and sets a work area are connected to the input circuit 2.
0 and display circuit 50 are connected to constitute a processing device PU. A tap switching lock circuit 53 is also connected to this processing device PU.

The input circuit 20 functions as an input interface and is connected to the pressure detection section S1. The detection signals from the operating shaft strain detection section S2 and the transmission shaft distortion detection section S3 are amplified and converted into digital signals. This input circuit 20 is activated by the CPU 90 each time the tap is switched, and the input circuit 20 is activated by the CPU 90 for each tap change.
It also has a function of performing sampling at a constant period from ~S3.

Based on the digitized detection signal, the arithmetic circuit 30 calculates the absolute value (peak value) of each detected change in pressure, change in operating shaft strain, and change in transmission shaft strain that occurs during tap switching. ) and the duration of the change. In addition, it is also possible to obtain an integral value. Further, regarding the pressure change, an average value may be determined.

The calculation port N30 has a memory for storing at least the amount of input data sent from the input circuit 20 for tap switching, and also for storing calculation results.

Specifically, a storage area for this purpose is set in the RAM 92.

The determination circuit 40 has a function as shown in FIG. 2B.

That is, when the detection signals of each of the detection sections 81 to S3 are not output at a certain level or higher at the time of tap switching, the detection signal presence/absence determination section 41 determines that the detection section itself is abnormal.
It has a to 41e. Further, when there is a detection signal, abnormality presence/absence determining units 42a to 42 compare the duration and absolute value of each detection signal with a set value to determine the presence or absence of an abnormality.
f, an AND circuit 45 that takes the logical product of the determination results of no abnormality in all of the abnormality determination units 42a to 42f, and all of the abnormality determination units 42a to 42.
an OR circuit 46 that performs a logical sum on the result that there is a serious abnormality in f, and the abnormality determination units 42a to 42d.
an OR circuit 43 that calculates the logical sum of the results indicating that there is a slight abnormality, and the abnormality determination units 42e and 42f.
It has an OR circuit 44 which takes the logical sum of the results indicating that there is a slight abnormality in .

The abnormality determination circuits 42a to 42f set a reference based on a multiple of a normal value. At this time, as described above, the multiples are set in two stages, large and small, to perform the two-stage determination of 5 serious abnormalities and minor abnormalities.

In addition, the switching switch alarm circuit 51 displays an alarm when there is an abnormality in the pressure rise in the switching switch or the operating shaft, and the switching switch alarm circuit 51 displays an alarm when there is an abnormality on the transmission shaft. If there is a serious abnormality in any of the monitoring points, a tap switching lock circuit J153 outputs an alarm and a signal instructing to stop the tap switching, and a detection signal is output. No detection signal display circuit 5 that displays this when there is no detection signal
4, and a normality display section 55 that displays that the system is normal when no abnormality is detected in any of the abnormality determination sections 42a to 42f.

This display circuit 50 only needs to be able to display each signal as described above.

In this embodiment, each lamp is displayed on the panel, but it is also possible to set an area on the screen of a display device such as a CRT and display each. In either case, the corresponding message is displayed. They can be displayed together. Further, the message may be outputted by voice, or a printing device may be used.

Next, the operation of the embodiment configured as described above will be explained.

At the time of tap switching, the input circuit 20 is activated by the CPU 90, and the above-mentioned pressure detection section S1 and operation shaft strain detection section S are activated.
The detection signals outputted from the input circuit 2 and the transmission shaft strain detection section S3 are amplified and sampled in the input circuit 20, and are converted into digital values.

These data are sent to the arithmetic circuit 30.

Second, data representing the state of the object to be monitored is obtained.

That is, the pressure changes as shown in FIG. 6A occur within a range of several seconds or less for one tap change. Therefore, the absolute value of the peak value of this pressure change and the duration of the pressure change are calculated.

In addition, the operating axis distortion is approximately 50% for one tap switching.
At about m5, as shown in FIG. 6B, distortion occurs and its magnitude changes. Therefore, the absolute value of the peak value of this change in distortion and the duration of the distortion are determined.

Furthermore, the transmission axial strain is approximately 5 for one tap switching.
Distortion occurs and changes in the waveform shown in FIG. 6C for about seconds. Therefore, the absolute value of the peak value of this change in distortion and the duration of the distortion are determined.

These calculation results are sent to the 1 determination circuit 40.

It is compared with the set standard to determine whether there is an abnormality.

The determination circuit 40 first determines whether or not each of the above-mentioned detection signals is present every time one tap is switched.

For example, if the calculation result output from the calculation circuit 30 is significantly smaller than the normal value, the detection signal presence/absence determination units 41a to 41c determine whether the corresponding detection unit is operating.

Alternatively, it is determined that tap switching is not being performed due to an abnormality in the tap switching power supply. Here, the WJ person.

This phenomenon can be distinguished depending on whether the result is part or all of the calculation result.

That is, if only a portion of the calculation results are abnormal, it is determined that the corresponding detection section is abnormal.On the other hand, if all the calculation results are abnormal, it can be determined that tap switching is not performed.

This result is sent to the detection signal no display circuit 54, and an alarm is displayed.

The reason why it is possible to determine the presence or absence of a detection signal as described above is as follows. That is, in the case of pressure detection, when changing the tap, an arc is generated regardless of whether it is normal or abnormal, and this causes the insulating oil to decompose and gas to be generated. This gas increases the pressure within the switching switch. Therefore, if the pressure detection signal remains at a low level even though tap switching has been instructed, it can be determined that tap switching has not been performed or that there is a malfunction in the pressure detection section S1 itself. .

Similarly, regarding operating shaft distortion and transmission shaft distortion.

Even if each axis rotates normally, a certain degree of distortion will occur, and this can be used to discover abnormalities in each detection unit S2 or S3.

It should be noted that simultaneous failure of all the detecting sections 81 to S3 rarely occurs because the probability of this occurring is low. Therefore, if there is no detection output from all the detecting sections 81 to S3, tap switching is not performed. In other words, it is thought that the driving force is not generated.

If a detection signal exists, the presence or absence of an abnormality is determined for each detection signal. The fJ1 determination is performed for the duration and absolute value calculated by the arithmetic circuit. Further, a lower judgment value and an upper judgment value are respectively set for these duration times and absolute values. The former corresponds to a minor abnormality that does not cause the device to stop, and the latter corresponds to a serious abnormality that requires the device to be stopped.

In this embodiment, these determination values are set as multiples of normal values. That is, the abnormality presence/absence determination circuit 42a
.about.42f, determination criteria such as numerical values shown in parentheses in FIG. 2B are set.

Now, if the absolute value of the pressure is, for example, more than twice the normal value, which is the lower judgment value, or if the duration is more than twice the normal value, the arc at the time of switching will extend in the switching switch DS. If some abnormality sign is considered, the determination result of the determination circuit 40 is led to the switching switch alarm circuit 51, and an alarm is displayed. Then, the absolute value of the pressure is, for example, three times or more of the normal value, which is the upper judgment value, or
When the Jll waiting time becomes more than four times the normal value, it is determined that the abnormality is progressing, and the determination result of the determination circuit 400 is guided to the tap switching lock circuit 53 that stops tap switching,
Stop tap switching by motor M. Of course, during normal operation other than that, it goes without saying that the determination result of determination s40 is guided to the normality display section 55 that displays normality.

Here, the explanation has been given by taking up the pressure detection section S1 as an example, but the same applies to the other operating shaft strain detection section S2 and the transmission shaft distortion detection section S3.

The absolute value and duration of the detected value are separately compared with normal values, and the results are led to an alarm circuit or a display section, respectively, by an AND circuit or an OR circuit.

The normal system constituted by the above embodiment is as follows.

By applying a trigger when switching taps, the detection units 81 to S3 can be activated each time. It becomes possible to monitor the overall operation status of the tap changeover. By doing so, you can further increase your credibility.

In the embodiment described above, the internal pressure of the switching switch.

We are detecting operating shaft distortion and transmission shaft distortion.
A configuration may be adopted in which detection is performed for one or two of them. In this case, it is preferable to include detection of internal pressure in the detection items. It is also preferable to monitor other items, such as the degree of contamination of the insulating oil and the amount of wear of the contacts of the switching switch, which will be described later.

Although the above embodiment is an example applied to a tap changer having a structure in which driving force is transmitted by a transmission shaft and the operating shaft is operated in an instantaneous manner, the present invention is not limited thereto; The present invention can be widely applied to tap changers on load that have a structure that includes means for transmitting opening force from a source, and operation means that is opened by the transmitting means and switches the tap changer. In this case, the transmission means is not limited to the above-mentioned transmission shaft, but the most suitable transmission means is selected from among a wide range of transmission bodies 1 having the function of transmitting driving force, such as rod-shaped members, cams, gear mechanisms, etc. Similarly, the operating means is not limited to the above-mentioned operating shaft, but includes a wide range of operating bodies that have the function of performing tap switching operations in response to the driving force from the transmission means, such as operating sticks, cams, gear mechanisms, etc. The most suitable one is selected from among them.

Therefore, the transmission shaft strain detection in the embodiments described above is an example of strain detection of the transmission means, and the operation shaft strain detection is an example of strain detection of the operation means.

Further, the processing device PU can be housed in the electric operating mechanism DM, for example, as in the following embodiments. Of course, it is not limited to this position, and it is also possible to provide it at other positions. An example thereof is to provide it in a separate control room 811 (not shown).

Furthermore, the display circuit 20 can be arbitrarily selected depending on its purpose. It is also a good idea to use a color display to easily distinguish between normal, alarm, and tap switching locks by color-coding the display screen.
Of course, it would be practical to further subdivide the content of display 9 and indicate whether the display is related to the switching switch or the transmission shaft, etc., so that you can see where the problem is occurring. It is.

Next, another embodiment of the present invention will be described.

This embodiment is an example in which the on-load tap changer of the embodiment described above is provided with a live line oil purifier. That is, when the live line oil purifier 15 is attached to the on-load tap changer LTC, the oil contamination degree detection section S4 is provided in the inlet side oil conduit 12. Note that this embodiment has the same structure as the above-described embodiment except for the live-line oil purifier.

In this embodiment, the explanation will focus on the differences.

The live-line oil purifier 15 has a filter medium 14a and a pump 14b inside, and is connected to a switching switch DS via an oil conduit 12.13.

As shown in FIG. 2C, the oil contamination degree detecting section S4 includes a light emitting section 81 and a light receiving section 82 with the inlet side oil conduit 12 interposed therebetween.

Further, the output of this oil contamination degree detection section S4 is
As shown in Figure A, the data is input to the processing device PU. That is, this processing device PU constitutes a monitoring means.

The input circuit 20 of the processing circuit PU has a function of sampling the output signal of the oil contamination level detection section S4 and converting it into a digital value. Furthermore, the arithmetic circuit 30 has a function of calculating the light transmittance based on the detection signal and holding the same.

On the other hand, the first determination circuit 40 includes a transmittance determining section 42g that determines whether or not the calculated light transmittance exceeds a set reference value, and a live line filter that determines whether or not the calculated light transmittance exceeds a set reference value. A stop instruction circuit 47 that instructs to stop the oil pump 14b, and an oil purifier control circuit that controls the pump 14b to continue operating when the permeability does not reach a set value.
1%48.

It has a contamination level calculation circuit 49 which receives the output signal from the control circuit 48, measures the time required for oil purification, and calculates the degree of contamination of the insulating oil. The display circuit 50 includes a stain degree display circuit 56 that displays the calculated stain degree.

Next, the operation of the fifth embodiment will be explained.

In this embodiment, the light transmitting portion 85 a ! This takes advantage of the fact that the amount of light transmitted through the light receiving section 85b and received by the light receiving section 82 changes.

The optical information detected by this oil contamination degree detection section S4 is input to the processing device PU shown in FIG. 2A, digitized by the input circuit 20, and further, the transmittance is calculated by the calculation circuit 30.

The calculated transmittance is determined by the transmittance determination unit 42 shown in FIG. 2B.
g, it is compared with a preset reference value. Note that the reference value is set to one time the transmittance corresponding to the permissible limit.

Here, if the standard value is not reached, that is, if the degree of contamination exceeds 1 times the standard value, the oil purifier control circuit 48 causes the live oil purifier 15 to continue operating until the level falls below the standard value. It is designed not to stop. This means that the state of the insulating oil 7 is always maintained in a state where it has sufficient dielectric strength, and serves to prevent accidents caused by deterioration of insulation.

In addition, as the oil contamination level detection section S4, a pair of electrodes 83.
The insulating oil 7 passing between the electrodes 83 and 84 may be configured by applying a voltage.
By detecting the withstand voltage value of with the detector 88,
Detects the degree of oil contamination. This also provides the same effect as the oil contamination level detection section shown in FIG. 2C.

In the present embodiment, the degree of contamination calculated by the degree of contamination calculation circuit 49 makes it possible to detect that a phenomenon in which the insulating oil is abnormally contaminated is occurring within the switching switch DS. That is, when the insulating oil itself is new, it can be considered that the abnormal contamination is caused by an internal abnormality, in particular, abnormal arcing or continuation of arcing.

Therefore, an operation monitoring system can be constructed only by monitoring the degree of contamination.

However, as shown in Fig. 1A above, it is preferable to combine this with monitoring such as pressure detection. It is more preferable to combine it with degree.

Next, another embodiment of the present invention will be described.

This embodiment is applied to a load tap changer for boat fishing, and FIG. 3 shows an outline of the configuration of this embodiment.

In FIG. 3, the on-load tap changer to which this embodiment is applied is configured to switch the tap 3 of the tap winding 2 of the transformer to the selector TS.
and a switching switch DS having a fixed contact 71 and a movable contact 72.

The monitoring system applied to this on-load tap changer is:
It is constituted by a current detecting section S5 provided at an arbitrary m-circuit end position for measuring the load current IO, and a processing device PU processing the current detected by the current detecting section S5.

For example, a current transformer is used as the current detection section S5.

The processing device PU is similar to each of the embodiments described above.
It can be configured with the hardware shown in Figure E.

This processing unit PU has five functions.

It is configured to include an input circuit 20, an arithmetic circuit 30, a determination circuit 40, and one display time j$50.

The input circuit 20 has the functions of sampling and digitizing the current signal in addition to the functions in each of the embodiments described above.

In addition to the functions in each of the embodiments described above, the arithmetic circuit 30 has the following functions:
It has a function to calculate the amount of contact wear and a function to store and hold the amount of contact wear up to that point.

The determination circuit 40, as shown in FIG.
It has almost the same configuration as shown in the figure. The difference is that a contact wear amount determining section 60 is provided at the subsequent stage of the OR circuit 43.

The display circuit 50 has the same structure as that shown in FIG. 2B, except that a contact replacement time display section 57 is added.

Next, the operation of this embodiment will be explained.

First, the current signal detected by the current detection section S5 is sent to the input circuit 20, converted to a digital value, and then sent to the arithmetic circuit 30.
sent to. In this arithmetic circuit 30.

The amount of wear of the contacts 71 and 72 is calculated for each tap change. The calculation result is led to the 1 determination circuit 40 together with the results from the pressure detection section S1, the operating shaft strain detection section 82, and the like.

At the same time, the information is sent to the contactor replacement time display section 57 to display the contactor replacement time. This allows operational convenience such as one-time replacement work.

Next, the calculation of the contact wear amount in the arithmetic circuit 30 is performed as follows.

In other words, the contact wear amount is the switching current to the nth power (-generally n''
It is experimentally known that it is proportional to F 1.6).

Therefore, by knowing the current value for each tap change, which is proportional to the load fluctuation, it is possible to determine the amount of contact wear for each tap change. By integrating this, you can get a highly accurate cumulative amount of consumption.

Here, if the amount of decolorizer consumption during one switching at the i-th time is ΔW, and the current at that time is ΔW, ΔWt is obtained by the following equation.

ΔW,'':IL Next, if the cumulative amount of consumption up to the (i-1)th time is W, -8, the cumulative amount of consumption WI at the i-th time is determined by the following equation.

W t = W t -1 + ΔW.

Therefore, the statistics of the amount of consumption can be determined by measuring the current every time the tap is switched, determining ΔW1, and sequentially adding the values cumulatively.

By the way, as the number of switching increases, the amount of wear on the contacts increases, and the amount of wear and tear imbalance between the contacts increases, the on-off time of the contacts of the switching switch increases.
In other words, the sequence time becomes longer and the arc generated during tap switching becomes longer. The contact wear amount determining section 60 utilizes this phenomenon. By sending the result to the contact wear determination section 60, if the switching switch DS
If the repulsion force increases higher than normal during normal operation, it may be due to a high probability of arc elongation due to large amount of contact wear. Is this caused by slow tap switching speed due to stiffness of the shaft?

It is also possible to estimate the phenomenon and make more reliable judgments.

The above-described embodiment is an example in which the functions of the other embodiments described above are combined in addition to the function of calculating the amount of contact wear. It is also possible to configure

[Effects of the Invention] According to the present invention, by providing a detection section for various changes such as pressure and distortion/contamination accompanying tap switching, and comparing the detected value with a reference value, the changeover switch, transmission section, etc. It is possible to provide an operation monitoring system that can predict problems related to the drive system in advance and prevent accidents of tap changers on load.

[Brief Description of the Drawings] Figure 1A is a block diagram showing the configuration of the on-load tap changer operation monitoring system of the present invention, and Figure 1B is used for the configuration of the on-load tap changer operation monitoring system of the present invention. FIG. 2A is an explanatory diagram showing the configuration of an embodiment of the on-load tap changer and its operation monitoring system of the present invention, and FIG. 2B is a determination circuit in the monitoring system of the present invention. 2C and 2D are block diagrams showing the functional configuration of one embodiment of the display circuit, and FIGS. 2C and 2D respectively show main parts of other embodiments of the on-load tap changer operation monitoring system of the present invention. Cross section, 2nd
Figure E is a block diagram showing an example of the configuration of hardware that can be used to configure the monitoring system of the present invention, Figure 3 is an explanatory diagram showing the configuration of still another embodiment of the monitoring system of the present invention, and Figure 4 is A block diagram showing another embodiment of a determination circuit and a display circuit that can be used in the configuration of the monitoring system of the present invention including the embodiment described above, FIG. 5 is an explanatory diagram showing the configuration of a conventional on-load tap changer, and FIG. @ is a graph showing changes in pressure over time, FIG. 6B is a graph showing changes in operating shaft strain over time, and FIG. 6C is a graph showing changes in transmission shaft strain over time. LTC...Tap changer on load, TS...Tap selector, DS...Switching switch, Sl...Pressure detection unit,
S2... Operation shaft strain detection section, S3... Transmission shaft distortion detection section, S4... Oil contamination level detection section, S5... Current detection section,
DM...Electric operation mechanism, 1...Transformer tank, 2
...Tap winding, 3...Tap, 6...Operation axis,
10... Transmission shaft. 15...Live oil purifier, 20...Input circuit, 30...
- Arithmetic circuit, 40... Determination circuit, 50... Display circuit, 4La to 41c... Detection signal presence/absence determination section, 42a to
42f...Abnormality determination section, 51...Switching N-closer warning N circuit. 52... Drive system alarm circuit, 53... Tap switching lock circuit, 54... No detection signal display circuit, 55...
Normal display area.

Claims (11)

[Claims] 1. An operation monitoring system for an on-load tap changer having a changeover switch in which a tap changeover operation is performed by driving an operating body using a driving force transmitted through a transmission body, the changeover switch device comprising: a pressure detection unit that detects a change in internal pressure; an operating body strain detection unit that detects strain occurring in the operating body;
Alternatively, the apparatus includes a detection means having at least one of a transmission body strain detection section that detects strain generated in the transmission body, and a monitoring means that monitors the operating state based on a detection signal of the detection means. An on-load tap changer operation monitoring system featuring: 2. An operation monitoring system for an on-load tap changer having a changeover switch in which a tap changeover operation is performed by driving an operating body using a driving force transmitted through a transmission body, the changeover switch device comprising: a pressure detection unit that detects a change in internal pressure; an operating body strain detection unit that detects strain occurring in the operating body;
and a load characterized by comprising: a detection means having a transmission body strain detection section that detects strain generated in the transmission body; and a monitoring means that monitors the operating state based on each detection signal of the detection means. Operation monitoring system for hourly tap changers. 3. An operation monitoring system for an on-load tap changer having a switching switch in which a tap switching operation is performed by driving an operating body using a driving force transmitted through a transmission body, the system comprising: a detection means having a current detection unit that detects the current at the time; and a function of calculating the amount of wear of the contact of the switching switch based on the current value, and monitoring the wear of the contact based on the calculation result. 1. An operation monitoring system for an on-load tap changer, comprising: monitoring means having the following. 4. The switching switch is equipped with a live-line oil purifier that purifies the insulating oil in the switching switch, and the operating body is driven by the driving force transmitted through the transmission body to perform the tap switching operation. An operation monitoring system for an on-load tap changer, comprising: a pressure detection section that detects a change in the internal pressure of the switching switch; an operating body strain detection section that detects strain occurring in the operating body; a detection means having at least one of the transmission body strain detection sections that detect strain generated in the transmission body and an oil contamination degree detection section that detects the degree of contamination of the insulating oil; and based on the detection signal of the detection means, 1. An operation monitoring system for an on-load tap changer, comprising: monitoring means for monitoring an operating state. 5. An operation monitoring system for an on-load tap changer having a changeover switch in which a tap changeover operation is performed by driving an operating body using a driving force transmitted through a transmission body, the changeover switch device comprising: a pressure detection unit that detects a change in internal pressure; an operating body strain detection unit that detects strain occurring in the operating body;
Alternatively, a detection means that includes at least a pressure detection section among the transmission body strain detection sections that detect strain occurring in the transmission body, and has a current detection section that detects a current at the time of tap switching of the tap winding. and monitoring means for monitoring the operating state based on the detection signal of the detection means, and the monitoring means monitors the wear and tear of the contactor of the switching switch based on the current value detected by the current detection section. It is configured to have a function of calculating the amount, monitoring the wear of the contact, and determining the relationship with the wear of the contact when there is an abnormality in the pressure detected by the pressure detection unit. An on-load tap changer operation monitoring system characterized by: 6. Pressure changes due to gas produced when insulating oil is decomposed by arcing when changing taps, distortion that occurs in the operating body of the switching switch when changing taps, and/or. A load characterized by detecting strain generated in a transmission body that transmits driving force to the operating body at the time of tap switching, and comparing these detection results with normal changes to detect an abnormality at the time of tap switching. How to monitor the operation of an hourly tap changer. 7. Any location where pressure is transmitted within the switching switch, any location where strain occurs in the operating body that performs the switching operation of the switching switch, any location where distortion occurs in the transmission body that transmits the driving force to the operating body. An on-load tap changer characterized in that a sensor for detecting pressure or strain is arranged at at least one position. 8. Based on the signal representing the state of the object detected by the sensor, at least one type of data among a peak value, duration, integral value, average value, cumulative value, and change pattern is obtained for the state, and this data and A condition monitoring method comprising: comparing a set determination standard to determine the presence or absence of an abnormality, and outputting the determination result. 9. a calculation means for calculating at least one type of data among a peak value, duration, integral value, average value, cumulative value, and change pattern regarding the state of the object based on a signal representing the state of the object detected by the sensor; , a condition monitoring device comprising: a determining means for comparing this data with a set determination criterion to determine the presence or absence of an abnormality; and an output means for outputting the determination result. 10. Based on signals representing the state of the object detected by a plurality of sensors, at least one of a peak value, duration, integral value, average value, cumulative value, and change pattern is determined for the state of the object. Calculate species data,
These data are compared with the set judgment criteria to determine whether there is an abnormality, and if there is no abnormality in any of the multiple judgment results, the system is considered normal, and if there is an abnormality in any of the judgment results, the system is determined to be normal. A condition monitoring method characterized by determining that the system is abnormal. 11. Based on signals representing the state of the object detected by a plurality of sensors, at least one of a peak value, duration, integral value, average value, cumulative value, and change pattern is determined for the state of the object. A calculation means that calculates the data and compares these data with set judgment criteria to determine the presence or absence of an abnormality, and if there is no abnormality in any of the multiple judgment results, the system is normal. What is claimed is: 1. A state monitoring device comprising: determining means for determining that the system is abnormal when there is an abnormality in any of the systems; and output means for outputting the determination result.