JPS6276226A - Vacuum switching unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vacuum switching device capable of monitoring the opening/closing life of a vacuum valve.

[Technical background of the invention and its problems] Conventionally, as shown in FIG. The vacuum valve 2 has a contact section sealed in a vacuum container, and an operation mechanism 3 for opening and closing the contact section.

In this type of vacuum switchgear, if the vacuum valve contact wears out beyond a certain limit (for example, 3 m),
The ability to turn on and off the main circuit current decreases. Therefore, monitoring vacuum valve contact wear is extremely important.

Therefore, conventionally, in the wipe spring section 4 that applies a constant surface pressure to the vacuum valve contact, when the vacuum valve contact is normal, the wipe spring section (when the vacuum switch is turned on) has a predetermined dimension as shown in Fig. 5. Regarding the dimensions, if the vacuum valve contact wears out beyond a predetermined size, the operating lever 4b connecting the vacuum valve 2 and the wipe spring section 4 will move in the direction of the arrow by an additional elongated hole 4C (the operating lever 4b is indicated by a dotted line), and the operation lever 4b will be closed. At that time, the dimension of the wipe spring 4a changed from L to L + W, and the amount of wear of the vacuum valve contact was detected by the change in the wipe spring dimension, etc.

However, in the above-mentioned vacuum switchgear, it is necessary to directly visually check the vacuum switchgear in order to check for wear and tear on the vacuum valve contacts, and also to check the wear field and remaining life of the vacuum valve contacts. It was not possible to visit the department directly, and it was not possible to monitor the situation online.

[Purpose of Defense 1] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a vacuum switching device that enables online monitoring of the electrical switching life of a vacuum valve and predicts the remaining life. With the goal.

[Summary of the Invention] In order to achieve the above object, the vacuum switchgear according to the present invention is provided with a current transformer in the main circuit conductor, and a breaking current value detected from the current transformer by a calculation means, and a pre-stored tolerance value. The present invention is characterized in that the opening/closing life of the vacuum valve is calculated based on the cumulative value of the ratio between the allowable number of interrupts and the number of interrupts for each interrupt current, and the allowable accumulation (directly) from the interrupting current characteristics.

[Embodiments of the Invention] Hereinafter, an embodiment of the vacuum switchgear according to the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of the vacuum switchgear of this embodiment, which has a monitor system for detecting the electrical life of the vacuum valve contacts. In the following drawings, the same parts as in FIGS. 4 and 5 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.9 In FIG. A current transformer 6 is mounted on the upper part of the frame of the operating structure 3 to calculate the electrical switching life of the vacuum valve 2 using a predetermined method (described later). ) is a computing device such as a microcomputer that issues an alarm, and is shielded to withstand noise components that accompany opening and closing.

Next, the calculation method of the calculation device 6 in the above configuration will be described. That is, the electrical switching life of a vacuum switchgear is generally approximated by a straight line on a logarithmic graph, as shown in FIG. For example, the allowable number of interrupts for current 11 is Nl, the allowable number of interrupts for current ii is NJ, the allowable number of interrupts for current in is Nn, 1 = kN (k, α = constant)... It is determined as ■.

1-G, when the current value of 1 watt is Ij from the current transformer 5, the allowable number of interruptions Nj of the current It is determined, and the actual number of interruptions of the actual current value 1j is ~1'', ~11 When the following holds true, what will be the electrical switching life of this vacuum switchgear?

Also, the breaking current is 11. +2. +3. ... ln, and the allowable number of interruptions is Ni, N2, ~ from formula (i).
3...When set to ~0, the number of actual interruptions is set to ~1 for each
1. \・12. N・13...N・l ``+, t:, then the formula is ;missing]'11: ('@, and when 2〇 is established, the electrical switching life of this vacuum switchgear is Become.

FIG. 3 shows blocks for implementing the calculation method of this embodiment based on the above principle. In FIG. 3, a command S2 is received from the outside in process P1, for example from an operation circuit (not shown), and it is determined in process P2 whether or not this is a shutdown command. It waits for a command, and in the case of a cutoff command (YES), outputs an output to that effect.

On the other hand, as a process P5 via process P4,
), as process P6, current detection 1j (one) is carried out, and if this detected value Ii is less than zero in process P7 (No), in process P8, it is unconditionally set to ``no energization'' [゛〈b, and zero. If the above is true (YES) and it is determined in process P9 (AND condition) that there is an interruption current at interruption P2, then process p
At H+, the allowable number of interruptions Mx from the processing pH matches, and in processing P12, the interruption current It becomes the number of interruptions N t 1. : Replacement, if processed <YES), a command to output an alarm to an online alarm circuit (not shown) is given as process P1s, and if the condition is not satisfied (No), input is waited for as process P14 (81, 82). Become.

Furthermore, it is also possible to mount the monitor system in the above embodiment on a power distribution board having a vacuum switchgear.

On the other hand, as a modification of 2〇, the following formula ■ is set, and C<1
...■ By establishing the AND condition in the above formula ■■, predictive maintenance of the electrical switching life of the vacuum switchgear is possible, that is, if it is C-1, it is life detection, but if it is C-1, it is in a state before it reaches the end of its life. can also be detected.

[Effects of the Invention] As detailed above, according to the present invention, a current transformer is provided in the main circuit conductor, and the breaking current value detected from the current transformer by the calculation means and the allowable breaking current characteristic stored in advance Since the opening/closing life of the vacuum valve is calculated based on the cumulative value of the ratio between the allowable number of interruptions and the number of interruptions for each interruption current, and the allowable cumulative value, the electrical opening/closing life of the vacuum valve can be monitored online. It is possible to provide a vacuum switchgear that makes it possible to predict the remaining service life.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a vacuum switchgear according to the present invention, FIG. 2 is a characteristic diagram showing an example of the electrical switching life characteristics of the vacuum switchgear, and FIG. 3 is a diagram showing an example of the electrical switching life characteristics of the vacuum switchgear. FIG. 4 is a block diagram showing a calculation method, FIG. 4 is a diagram showing an example of a conventional vacuum switchgear, and FIG. 5 is a diagram explaining a conventional method for measuring the amount of wear of a vacuum valve contact. 1... Main circuit disconnection section, 2... Vacuum valve, 3...
Operation mechanism, 4... Wipe spring section, 5... Current transformer, 6
... Arithmetic device (microcomputer). Applicant's agent Patent attorney Takehiko Suzue g$1 Figure 4 Flash jIS diagram

Claims (1)

[Claims] In a vacuum switchgear in which a vacuum valve that opens and closes the main circuit current is inserted in the main circuit conductor, a current transformer provided on the main circuit conductor and the breaking current value detected by this current transformer are stored in advance. A vacuum switching device characterized by comprising: a cumulative value of the ratio between the allowable number of interrupts and the number of interrupts for each interrupting current from the allowable interrupting current characteristics, and calculation means for calculating the opening/closing life of the vacuum valve based on the allowable cumulative value. Device.