JPS63249068A - Preventive maintenance of switching apparatus - Google Patents

Abstract

PURPOSE:To discriminate the cause of the operation time delay of an auxiliary switch and to reduce the labor of maintenance, by measuring the time from the start of the supply of a current to a making or cut-off coil to the predetermined position properly set in the entire stroke of switching apparatus. CONSTITUTION:When the data relating to making operation are compared with the values immediately after manufacturing of said measured data, all of individual compared quantities coincide with the values immediately after manufacturing within a tolerant error range in a case C and a switching apparatus is judged to be normal but, in a case D, not only the operation times t4, t5 of an auxiliary switch but also the time t7 reaching the position 10% of the entire stroke of the switching apparatus from the start of the supply of a current to a making coil 12 and the time t3 reaching the position 90% of the entire stroke exceed a tolerant range in difference as compared with the values immediately after manufacturing. However, since the time between 10% and 90% of the entire stroke is normal, a phenomenon of tightness and reluctance is judged to be a cause in this case.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a preventive maintenance method for detecting malfunction of switching devices such as circuit breakers and disconnectors to prevent accidents. This invention relates to a preventive maintenance method for determining the presence or absence of an abnormality in the switching equipment by individually comparing various quantities related to the operation of the equipment with values immediately after manufacture, and for preventing accidents in the switching equipment caused by the abnormality.

[Conventional technology]

In recent years, due to the increase in the amount of electric power equipment and social demands for a stable supply of electric power, reducing equipment failure has become a major issue in operation and maintenance. Among them, switching devices such as circuit breakers and disconnectors are always in a static state, but once they are given an operation command due to an accident in the power transmission and distribution system or a switchover, they must operate reliably. If a malfunction occurs such as inability to shut off or power on, the impact will be extremely large.

Before a serious failure occurs, such as an inability to turn off or turn on, some kind of precursor often appears as a change in control current, switching speed, opening/closing time, etc., so it is important to understand these changes in advance. Preventive maintenance devices for this purpose have been proposed in the past. The principle of this prior understanding is, for example, by comparing the measured values of various quantities such as control current, opening/closing speed, opening/closing time, etc. with the values at the time of manufacture, and if it is within the allowable S plate, it is normal; If not, it is determined that there is an abnormality.

[Problem that the invention seeks to solve]

The problems with the above method of abnormality determination are as follows.

Figure 5 shows that various quantities related to the closing operation of the circuit breaker were measured during the closing operation of the circuit breaker, and these measured values were compared with the values immediately after the circuit breaker was manufactured to verify whether the differences remained within the allowable range. Each item in Figure 0, which shows an example of the results, is the first maximum value i1 in the applied coil current shown in Figure 6. First minimum value i2. Second maximum value i3° Time point t1 when the first maximum value 11 is given.
Time point t2e when the first minimum value is given; second maximum value i3 is H
The time point t3. Time t4 when the b contact, which is an auxiliary contact that works with the circuit breaker main body and is opened when the circuit is closed, opens.
゜ Time t5 of the closing of the a contact which is closed at the time of closing and 10% and (3)% of the total stroke at the time of closing shown in FIG.
shows the time t6 required to move the stroke S, i.e. % of the total stroke, between , and in case B, the time t of the auxiliary switch
4. This shows a case where ts is compared with a normal value and the difference is not within the allowable range. As shown in FIG. 8, the average speed during the stroke S is measured by marking a bar code 14, which is painted in black and white at equal intervals, in the section Sl corresponding to the stroke S with the movable contact of the circuit breaker. 11, and the fiber sensor 2 detects the change in black and white of this barcode.

This is performed using the time width (t6) in which this change was detected.

Therefore, the scene detected by this measurement is only the time width t6, and the curve nods in Fig. 7 are stroke/time characteristic curves assuming that both ends of this time width are at 10% and 90% of the total stroke, respectively. . In addition, in FIG. 8, 10 is a fixed contact, 12 is a closing coil, 13 is a breaking coil, 1
5 is a measuring instrument.

In recent years, many circuit breakers are hydraulically driven.

In this case, the interlocking between the circuit breaker body and the auxiliary switch is often performed via hydraulic pressure. Therefore, as mentioned above,
If an abnormality is found in the opening or closing time of the auxiliary switch, this abnormality is not caused by the auxiliary switch, since the quantity indicating the operation of the breaker main body, such as the average speed V, is normal. It has been determined that this is due to a malfunction of a hydraulic piston that is mechanically connected and driven by hydraulic pressure, or a malfunction of the valve mechanism that applies hydraulic pressure to this hydraulic piston, and 9-9 disassembly and inspection work is carried out to confirm the cause of the malfunction. will be carried out. However, in many cases, no abnormality was found in the hydraulic piston or valve mechanism.

An object of the present invention is to provide a preventive maintenance method that solves the problems in the conventional abnormality determination method and can prevent accidents in switching equipment caused by true abnormalities.

[Means for solving problems]

This invention is based on the fact that the circuit breaker is always in a stationary state, and once it starts moving from this stationary state, it normally operates completely normally. It is difficult to detect true abnormalities by measuring only the average velocity of the movable contact (see Figures 7 and 8) after the circuit breaker has started moving. Focusing on the fact that it is difficult to discover the true cause of an abnormality unless measurements are made that focus on the evaluation of the transition process, we calculated various quantities related to the operation of switchgear from the values immediately after construction. Compare each item to determine whether there is an abnormality in the switching equipment.

In a preventive maintenance method for preventing accidents in switchgear caused by this abnormality, the various quantities to be compared are measured at least from the start of energization of the closing coil or cutoff coil to the first predetermined position during the entire stroke of the switchgear. , the time to the second predetermined position, and the time to the first predetermined position. and the time between the second predetermined positions.

[Effect]

When switching equipment is in a stationary state, frictional force increases due to running out of grease in the operating mechanism, solidification of grease, intrusion of dust, rust, etc. The movement of the operating mechanism may be stiff, resulting in a phenomenon of reluctance to move.

When such a stiffness phenomenon occurs, even if the average speed during the stroke is normal, it may be necessary to adjust the settings appropriately during the entire stroke of the switchgear from the start of energization of the closing or disconnecting coil, for example, at the initial stage. In such cases, the time it takes to reach the new position or the time it takes to reach the first position in the final stage clearly shows a difference compared to normal times.

For example, there is a delay in the supply of hydraulic pressure to a hydraulic piston that is mechanically coupled to an auxiliary switch that is interlocked with the main body of the switching device, and as a result, there is a delay in the opening and closing of the auxiliary switch. In the past, only the operation time of the auxiliary switch was measured, so the delay in operation time was determined to be caused only by malfunction of the hydraulic piston. By measuring the time from the start to an appropriately set predetermined position during the entire stroke of the switchgear, we can determine that the delay in the operation time of the auxiliary switch is due to a stiffness phenomenon in the operating mechanism or the main body of the switchgear including the operating mechanism. It will be a good idea to correctly determine that it was caused by the accident. In addition, in the present invention, various quantities compared with normal times of the switching equipment are the first. In addition to the time to the second predetermined position, this first. Since the time between the second predetermined positions is also measured, if this time is different from the normal value, it means that the average speed within this time is different from the normal value.
Said happiness 1. Even if the two times to reach the second predetermined position are not normal, for example, as in the previous example, they are longer than normal.

The cause is not necessarily a phenomenon in the early stages of operation, such as stiffness of the opening/closing equipment, but, for example, deformation of the movable parts or the members that guide the movable parts. It has been suggested that the cause may be an increase in frictional force over the entire stroke, resulting in a more rational and lean disassembly.

This can contribute to investigating the cause that makes inspection work possible. , [Example] Figure 1 shows measurements based on the present invention. Case C shows an example of the comparison results between various quantities related to the feeding operation and the values of these measured quantities immediately after dyeing. In this comparative example, case C shows that all of the individual quantities compared The values match within the allowable error range, there is no abnormality in the switchgear, and the switchgear ζ is determined to be normal.In case D, the operating time of the auxiliary switch is '4 v 'l! In addition, the time t7 from the start of energization of the closing coil to the position of 10% of the total stroke of the switchgear, and the time t8 until the position of 90% of the total stroke of the switching device are Indicates that the difference exceeds the allowable range compared to the value. However, the whole stroke 1
Since the time t78 between 0% and 4% is normal, the opening/closing equipment is operating completely normally once it starts moving*
'? It can be seen that the abnormality at +t8 is mainly caused by the stiffness phenomenon at the time of starting. Therefore, it was assumed that the abnormality in '4 e t5 was caused by this sticky phenomenon, and the hydraulic piston mechanically connected to the auxiliary switch and the valve mechanism that led the hydraulic pressure to this hydraulic piston were disassembled.

Before inspection, first remove the cause of the sticking phenomenon, such as running out of grease, and then operate the opening/closing equipment again.
If the measured value of 41'5 returns to a normal value, the cause is determined to be a stubborn phenomenon, and if it still shows an abnormal value, the above-mentioned disassembly and inspection work will be performed for the first time. Therefore, by adding the amount of pedal effort related to the transition process from a stationary state to a moving state as a measured quantity as in the present invention, it is unnecessary to perform work that requires time to disassemble and inspect, such as with a hydraulically driven operating mechanism. maintenance effort is significantly reduced.

Figure 2 shows the measurement results of various quantities that gave the comparison results in Figure 1.
7 and the time t8 to reach the 90% position are normal stroke characteristic curves, and the curve n is the above-mentioned t7 e tl
l are both abnormally long and the time t between the two positions
This is an assumed stroke characteristic curve when only ys is normal.

An example of a measuring device for measuring the time shown in FIG. 2 1cl is shown in FIGS. 3 and 4.

As shown in FIG. 3, the barcode l, which has a length Ll corresponding to the entire stroke of the circuit breaker and moves in a straight line mechanically interlocking with the circuit breaker main body, is 0.00 mm from the left end. IL□ position and 0
．． A black bar is marked at the position 9L1, and the change in black and white of this barcode is recorded via the fiber sensor 2. This record is different from previous records.

A signal to start energization of the closing coil is given to the recording device so that recording starts from the time when energization of the closing coil starts, and the operating state of the circuit breaker main body during the transition process from the stationary state to the moving state of the circuit breaker. It is possible to distinguish between normal and abnormal.

Figure 4 shows a bar code formed in the shape of a disk, which can be attached to the operating shaft of the operating mechanism of the circuit breaker. 0.10
Thin fan-shaped black marks are attached at the positions of and 0.90, and changes in black and white on one disk are recorded via the fiber sensor 2. In this case as well, recording is performed from the time when the closing coil starts energizing, so that it is possible to determine whether the operating state of the circuit breaker body is normal or abnormal during the transition from the stationary state to the moving state of the circuit breaker. .

〔Effect of the invention〕 As described above, according to the present invention, the S disconnector.

Switching devices such as disconnectors usually operate perfectly normally once they start working, so in order to discover abnormalities in switching devices, it is necessary to measure only the quantities obtained in the stationary state and the quantities obtained in the operating state. It is not always possible to make an accurate judgment just by comparing the values when the switchgear is in normal operation, and unless you also compare the values that indicate the state of the switchgear itself during the transition from the resting state to the moving state. Focusing on the fact that it is difficult to accurately understand the causes of abnormalities in measured quantities, we compare various quantities related to the operation of switching equipment with the values immediately after manufacture to determine whether there are any abnormalities in the switching equipment. In a preventive maintenance method for preventing accidents in switching equipment caused by this abnormality, the various quantities to be compared are determined at least during the first period during the entire stroke of the switching equipment from the start of energization of the closing coil or cutting coil. (t7), the time (t8) to the second predetermined position, and the time (t8) to the first predetermined position. The time between the second predetermined position (tys) is assumed to include the time (tys) between the second predetermined position, and therefore the grease running out and the grease solidifying in the operating mechanism of the opening/closing equipment.

After first determining whether there is a hardening phenomenon at the initial stage of operation due to dust intrusion, rust, etc., if t78 matches the normal value, the hardening phenomenon is confirmed as the cause of the abnormality, and tγ8 is set to the normal value. For example, when the time is longer than the normal value, causes other than the rigidity phenomenon must be investigated, and unnecessary errors based on erroneous judgments that could only be obtained from the comparison results of various quantities that were conventionally measured, should be investigated. In addition, the user is freed from long-time consuming work, and truly wasteful disassembly and zero-inspection work is possible.

[Brief explanation of drawings]

FIG. 1 was measured according to the present invention. An abnormality determination table showing an example of the results of comparison between various quantities related to the charging operation and the values of these measured quantities immediately after manufacture. FIG. 3 is an explanatory diagram of one measuring device for time measurement based on the present invention, FIG. 4 is an explanatory diagram of another measuring device, and FIG. 5 is an oscillogram shown together with the measurement results. An anomaly determination table showing an example of the comparison results between various quantities related to the charging operation and the measured values of these quantities immediately after manufacture. Figure 6 shows the measurement results of some of the conventionally measured quantities. Fig. 7 is an oscillogram showing an example of the results of time measurement to determine the average closing speed of switching equipment, and Fig. 8 is an explanatory diagram showing an example of the configuration of a measuring device for measuring time shown in factor 7. It is. 1]... Movable contact, 12... Closing coil, 13...
...Cutoff coil, t7... Time from the start of energization of the closing coil until the movable contact reaches the first predetermined position during the full stroke, ts... Similarly, the time until the movable contact reaches the second predetermined position. Time, hs...The movable contact is the first. The time required to pass between the second predetermined positions. , Figure 1 Figure 3 Figure 4 Figure 5 Do-1111 Figure 7 Possible *4 Ia Salmon Figure 8

Claims (1)

[Claims] 1) A preventive maintenance method that compares various quantities related to the operation of switching equipment with the values immediately after manufacture to determine the presence or absence of abnormalities in the switching equipment, and prevents accidents in the switching equipment caused by these abnormalities. , the quantities to be compared are at least the time from the start of energization of the closing coil or the cutting coil to the first predetermined position during the entire stroke of the switching device;
A preventive maintenance method for a switchgear device, the method comprising: a time to a predetermined position; and a time between the first and second predetermined positions.