JPH0195507A - On-load tap changer - Google Patents

Abstract

PURPOSE:To facilitate maintenance by securely detecting in early time any abnormal operation in a changeover unit by detecting the abnormal operation by comparing with a reference value a temporal change in an operation sequence of the unit on the basis of an output from a sensor. CONSTITUTION:When a change unit 2 of a tap changeover unit in loading is operated, mechanical collision sounds and vibrations, which are produce owing to collision between movable and fixed contacts 21, 20 of the changeover unit 2, are detected. The operation sequence of the changeover unit 2 is estimated by determination of a time difference between intervals of generation of such sounds and vibrations and a reference generation interval. Hereby, the life times of the contacts 20, 21 of the changeover unit 2 can be estimated from a change of the operation sequence with time to reduce the number of inspections for easing the maintenance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an on-load tap switching device, and more particularly to an improvement in an abnormality detection device for detecting an abnormality in the operation of a switching switch.

(Prior art) In general, a load-on tap switching device is composed of a switching switch, a tab selector, and an electric operating mechanism that drives them. It has the function of keeping the voltage of the power transmission and distribution system constant. The above-mentioned on-load tap switching device is JEC-
Electrical life 2 as specified in 186-1976
A high level switching capability with a mechanical life of 800,000 cycles per 800,000 cycles is required.

Conventional abnormality detection means for on-load tap changers, which require high frequency switching capability and high reliability in addition to high reliability, are to detect abnormalities through periodic table inspections by maintenance personnel, and to detect abnormalities inside the switching switch container. A common method is to detect an abnormal phenomenon using an oil flow relay, which detects an increase in oil flow due to a pressure increase due to an abnormal arc phenomenon that occurs in a motor.

(Problems to be Solved by the Invention) However, the abnormality detection means of the on-load tap switching device as described above has the following problems. That is,
The oil flow relay is configured to detect the flow of oil by the abnormal arc generated inside the switching switch container generating oil decomposition gas and increasing the pressure inside the switching switch container. With this method, it takes time from the occurrence of an abnormality to the pressure rise.

Early detection of abnormal phenomena was difficult. Furthermore, since the cause of the abnormal arc phenomenon could not be identified, the cause was investigated by internal inspection of the switching switch. Furthermore, if you regularly inspect the inside of the switching switch, you will need to carry out frequent inspections.
The drawbacks are that the maintenance and inspection are troublesome and the reliability of abnormality detection is poor.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to provide an on-load tap switching device that can detect abnormalities in a switching switch quickly and reliably, is easy to maintain, and is highly reliable.

[Structure of the invention]

(Means and effects for solving the problem) In order to achieve the above object, the present invention provides a sensor that detects the sound and vibration generated during operation of the switching switch, and the movable contact of the switching switch is replaced with a fixed contact. In a determination unit that detects the mechanical collision sound at the time of a collision and the vibration at the time of the collision and determines the operation sequence of the switching switch, a temporal change in the operation sequence of the switching switch based on the output from the sensor is performed. is compared with the standard value to detect abnormalities in the switching switch.

It is characterized by the fact that

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an on-load tap switching device according to an embodiment of the present invention. 1 is a tank of the transformer, 2 is a switching switch of the on-load tap switching device suspended inside the tank 1, 3 is also a tap selector, and 4 is a switching switch 2 provided outside the tank 1. An electric operating mechanism for driving the on-load tap changer consisting of a tap selector 3, 5 is a swinging changeover switch 2 attached to the tank top lid 2a of the changeover switch 2;
A sensor that detects the sound and vibration that occurs during switching operation, φ
An amplifier connected to the L sensor 5, a bandpass filter connected to the expansion amplifier 6, a determination section 8 that processes the signal of the bandpass filter and determines an abnormality in the operation sequence of the switching switch 2, and a determination section 9 connected to the determination section 8; The connected trip circuit, 10 is an abnormality display section for displaying an abnormality in the switching switch connected to the judgment section 8, and 11 is a section for transmitting a switching signal of the tap switching device under load to the judgment section 8 and the electric operation mechanism 4. Operation signal generator to send.

Reference numeral 12 indicates an energy storage device of the switching switch 2, 20 indicates a fixed contact of the switching switch 2, and 21 indicates a movable contact.

Next, regarding the operation of this embodiment configured as described above,
This will be explained using FIGS. 2 to 4. Figure 2(a),
(b) is a fixed contact 201 provided in the switching switch 2.
206 and movable contacts 211 to 216 operate normally. In Fig. 2 k), movable contacts 211 to 216
When the switching operation is performed from the entry side to the B side centering on the origin 0, the second
Each contact is turned on and off according to the sequence shown in Figure (b). By the way, when each contact is turned on, the movable contact collides with the fixed contact, so that metal collision noise and vibration due to the impact at the time of collision are generated as shown in FIG. 2(b).

FIG. 3 is an explanatory diagram of a case where the contacts of the switching switch 2 are evenly worn out due to a long period of current interruption and operate abnormally.

In Fig. 3(a), the second resistance contact 203゜2゛13 is in front;
When the L movable contacts 211 to 216 start switching from the entry side to the B side centering on the origin 0, the fulcrum P connected to the movable second resistance contact 21'3 is shown in FIG. Even if the movable second resistance contact 203 rotates to the position where it collides with the movable second resistance contact 203 in the normal state shown in FIG.
Further, when the origin 0 rotates from the entry side to the B side, the movable second resistance contact 213 collides with the fixed second resistance contact 203 with a time delay of ΔT, as shown in FIG. Similarly, the collision time of contacts 214 and 204, the contact time of contacts 215 and 20
As shown in FIG. 3(b), there is a time difference between the collision time of No. 5 and the collision time of the contacts 216 and 206 compared to the normal state.

The sensor 5 shown in FIG. 1 detects the metal collision sound generated when the movable contacts 211 to 216 of the switching switch 2 collide with the fixed contacts 201 to 206.

Vibration is detected, and the judgment unit 8 passes it through an amplifier 6 and a bandpass filter 7, and compares it with a preset standard value for collision noise and vibration that occurs during normal operation.This time difference ΔT is calculated. If the limit value is exceeded, an indication to replace the contacts due to uneven contact wear is displayed on the abnormality display section 9.

Next, other abnormality detection functions will be explained using FIGS. 1 and 4.

It is shown in Figure 1. When the operation signal generation unit 11 of the on-load tap changer sends a switching signal to the electric operation mechanism 4 of the on-load tap changer, the electric motor (not shown) of the electric operation mechanism 4 rotates, and the energy storage device of the switching switch 2 is activated. 12 performs a high-speed operation and moves the movable contact 21. As shown in Fig. 4, the switching switch 2 is activated at a time T1 after receiving the operation start signal of the on-load tap changer. Work.

As shown in FIG. 3(b), sound or vibration is generated for a period of time T.

At this time, if an abnormality such as a breakage of the energy storage spring (not shown) of the energy storage device 120 occurs, the high-speed operation of the energy storage device 12 will be slow (#), and as shown in FIG. The generation time extends from T to T'.

Next, when an abnormality such as breakage of the catch spring (not shown) of the energy storage device 12 occurs, the switching switch operation start time T during normal operation shown in FIG. Like T, shorten to Shi, and more sound.

The vibration generation time is extended to T''.

Also, if an abnormality occurs such as the switching switch 2 stopping at a halfway position, a sound will be heard as shown in FIG. 4 (e).

The generation time of vibration is shortened to T″', the intensity of generation of sound and vibration is high, and the number of times of generation of sound and vibration is reduced.

When the above abnormality occurs, the determination unit 8 shown in FIG.
The operation start time T1 of the switching switch from the operation start signal of the on-load tap changer and the operating time T of the switching switch are compared with standard values, and if they are outside the limits of the standard values, the trip circuit section 9 The abnormality display section 10 displays the type of abnormality.

The lock and bandpass filter 7 are 50 to 120Hz of the transformer.
This is a filter that removes high-frequency components such as self-excited vibration components and lightning impulses, and passes only the frequency component of one mechanical collision.

〔Effect of the invention〕

As explained above, according to the present invention, mechanical collision noise and vibration are generated when the movable contact and the fixed contact of the switching switch collide with each other when the switching switch of the on-load tap changer operates. The operation sequence of the switching switch can be determined by detecting the occurrence interval of these sounds and vibrations and measuring the time difference between the standard occurrence interval. The service life of the contacts can be detected, reducing the number of inspections per inspection and making maintenance easier. In addition, the difference between the operation start time of the on-load tap changer and the operation start time of the switching switch and the operation time of the switching switch are compared with standard values, and if they are outside the limit values, it is determined that there is an abnormality. Therefore, compared to a conventional detection method using an oil flow relay or the like, an abnormality can be detected early and reliably before a large amount of oil decomposition occurs due to the occurrence of an abnormality.

[Brief explanation of the drawing]

゛Fig. 1 is a schematic configuration diagram of an on-load tap switching device according to an embodiment of the present invention, and Fig. 2 (a), (b) and Fig. 3 (a), (b) are also an embodiment of the present invention. This figure shows normal and abnormal conditions in the example, (&) is a plan view of the contact part, (
b) is an operation sequence diagram, and FIG. 4 is an operation sequence diagram showing another embodiment of the present invention. 2...Switching switch, 3...Tap selector h 4...
・Electric operation mechanism, 5...sensor, 6...amplifier, 7
. . . band pass filter, 8 . . . determination unit, 9 . . . trip circuit. DESCRIPTION OF SYMBOLS 11... Signal generation part, 20,200-206... Fixed contact, 21,211-216... Movable contact. Applicant's agent Patent attorney Takehiko Suzue (a) (b)

Claims (1)

[Claims] A sensor is installed to detect the sound and vibration generated during operation of the switching switch, and detects the mechanical impact sound when the movable contact of the switching switch collides with the fixed contact and the vibration at the time of the collision. In the determination unit that determines the motion sequence,
An on-load tap switching device that detects an abnormality in the switching switch by comparing a temporal change in the operating sequence of the switching switch based on the output from the sensor with a reference value.