JPS61288407A - On-load tap changer - Google Patents

Abstract

PURPOSE:To enable to take a proper measure at early stages before a trouble develops into a serious one by monitoring a working part and to contrive improvement in the reliability of the title tap changer by a method wherein a detecting unit, consisting of a light-emitting part and a light-receiving part, on the working part of a change-over switch, and a decision part is connected to the detecting unit. CONSTITUTION:The operational condition of the movable contact point of a change-over switch 4 is monitored by a detecting part 6. One end of an optical fiber 7 is connected to the detecting part 6, it passes through the coupling part 10 attached to a part of the top section 5 of an on-load tap changer and connected to the judgement part 8 provided outside. For example, when the reference value of switching time is set at the decision part 8 in accordance with switching sequence, the abnormality of the tap changer can be judged by comparing said change-over time and the detected time at all times. When a decision is given as abnormal, a signal is immediately outputted from the decision part 8, the disposition can be performed at an early stage by having a constitution wherein the power source on the primary side of a transformer is tripped, thereby enabling to prevent a serious accident.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an on-load tap switching device for switching the taps of a transformer while the load current is flowing, and particularly relates to an on-load tap switching device that detects the operation of a switching switch and improves reliability. This relates to products with improved characteristics.

[Technical Preface to the Invention III: A load tap switching device installed in a transformer in a power transmission and distribution system is a tap changer installed in a transformer in a power transmission and distribution system, when the load in the power transmission and distribution system fluctuates and the voltage change due to this fluctuation exceeds a certain limit. The voltage of the power transmission and distribution system is kept constant by switching the installed taps.

This on-load tap changer is comprised of a switching signal generator, an on-load tap changer, and an electric operating mechanism, and the on-load tap changer is further comprised of a switch*W1 device and a tap selector.

In the device having this configuration, an outline of the switching operation is as follows. That is, when the voltage change exceeds a certain limit, a signal is first generated in the switching signal generator, which starts the electric operating mechanism and drives the on-load tap changer. As a result, the drive shaft of the on-load tap changer rotates, and this driving force moves the movable contact of the tap selector away from one fixed contact and into the other fixed contact. The switching switch performs a switching operation from one tap to the other tap.

FIG. 3 is a switching circuit of a two-resistance type on-load tap changer. TW is the transformer tap winding and T+.

T2 is the tap of the tap winding to which the tap selector fixed contact is connected. M + + M 2 is a movable contact of a tap selector, and is composed of a pair of odd number tap selection and even number tap selection. HA, HB are main contacts, WA, WB
is a resistance contact, R is a current limiting resistor, and S is a movable contact.

FIG. 4 is a sequence factor showing the switching order of the switching circuit of FIG. 3, and based on this figure, the switching order from main contact HA to HB will be explained. First, in the operating state, the main contact HA is closed and the load current is flowing.

The resistance contact WA closes due to the operation of the energy storage mechanism (not shown),
Then, after tl, the main contact HA opens. As a result, the main contact H
A interrupts the load current and transfers this load current to the resistive contact W.
Move to A. After t2, the resistance contact WB closes, and then after T3, the resistance contact WA opens, transferring the load current to the lower tap 2 side. Furthermore, after t4, the main contact HB closes, transferring the load current from the resistive contact WB to the main contact He, thereby completing the switching operation.

In a resistive load tap changer, the switching time 1i1T in the entire process as described above is a short time of 2 to 3 cycles, so the heat capacity of the current limiting resistor R can be reduced, and the overall configuration can be made smaller. have.

[Problems with the background art] By the way, if the on-load tap switching device breaks down, especially in the main power transmission and distribution system, there is a possibility of a widespread power outage. It is necessary to detect, recognize, and take action as soon as possible.

Conventionally, failure detection means for on-load tap switching devices include:
A device that detects the oil flow, gas flow, and gas pressure when the insulating oil or gas decomposes due to abnormal arcing that occurs inside the tap changer on load, and a large amount of gas is generated.The current that flows through the tap changer on load. There are methods that measure the magnitude of the current using a current transformer and detect short circuits between taps.

However, the conventional on-load tap switching device as described above has the following drawbacks.

In other words, if a load tap changer fails, it will cause a serious accident if it is not dealt with urgently, so it is necessary to detect the failure earlier. When an accident occurs such as an abnormal arc phenomenon or a short circuit between taps inside a tap changer, even if this is detected, the accident or accident has already spread and the tap changer or transformer is damaged under load. There may be cases where it is not possible to protect the

In particular, on-load tap changers are electrically
The specified lifespan is 100,000 times and 800,000 times per chance, and because the lifespan varies greatly depending on the quality of maintenance and inspection, accidents such as abnormal operation of switching switches due to mechanical damage occur. The probability of doing so is increasing. Such an accident has been a problem because it may develop into a serious accident such as melting of the arc contact that interrupts the current of the switching switch or melting of the current limiting resistor.

[Object of the Invention] The present invention was made in order to solve the problems of the prior art as described above, and its purpose is to prevent serious accidents by making it possible to detect abnormalities in the operation of switching switches. It is an object of the present invention to provide a highly reliable on-load tap switching device that can prevent accidents from occurring.

[Summary of the Invention] The on-load tap switching device of the present invention is characterized in that a detecting section consisting of a light emitting section and a light receiving section is provided in the operating section of the switching switch, and a determining section is connected to the detecting section. be.

With such a configuration, the operational state of the switching switch can be constantly monitored, so abnormalities in operation can be quickly detected and determined, and serious accidents can be prevented.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

*Configuration* FIG. 1 is a diagram showing the configuration of the on-load tap changer excluding the electric operation mechanism among the on-load tap changers. 1
is a transformer tank, and the head 5 of the on-load tap changer is mounted on the cover of this transformer tank 1. Reference numeral 2 denotes an insulating tube, the upper end of which is fixed to the head 5 of the on-load tap changer, and the tap selector 3 suspended from the lower end. A switching switch breaker 4 is built inside the insulating cylinder 2, and the switching operation as shown in FIG. 4 is performed by the instantaneous operation of the energy storage mechanism 9. Reference numeral 6 denotes a detection unit that monitors the operating state of the movable contact of the switching switch 4 (movable contact S in FIG. 3). Reference numeral 7 denotes an optical fiber whose one end is connected to the detecting section 6, which passes through a connecting section 10 attached to a part of the head 5 of the on-load tap changer, and connects to a determining section 8 provided outside.
connected to.

FIG. 2 is a structural diagram showing the detection section of FIG. 1.

Reference numeral 11 indicates a fixed contact, and reference numeral 12 indicates a movable contact that is disposed opposite to the fixed contact 11 and performs reciprocating operation with a predetermined opening distance from the fixed contact 11. 14 is a light emitting section for monitoring the operation of the movable contact 12, and 15 is a light receiving section that receives the light from the light emitting section 14 and detects the position of the movable contact. A plurality of optical fibers 13 are connected to the light emitting section 14 and the light receiving section 15.

*Effect* Next, the action will be explained. Necessary light is constantly transmitted to the light emitting section 14 through the optical fiber 13, and is received by the light receiving section 15 disposed opposite to the light emitting section 14 and transmitted to the determining section 8. Since movable contacts are arranged in the light emitting part 14 and the light receiving part 15 as shown in the figure, light reception is blocked at the position where the movable contact 11 was present, and thereby the presence of the movable contact 11 is detected. .

Therefore, according to this embodiment, the movement of the movable contact 12, that is, the operating state of the switching switch can be constantly monitored. Therefore, it is possible to immediately determine if the switching time has been delayed due to wear of various parts due to multiple switching operations. For example, if a reference value for the switching time according to the switching sequence shown in FIG. 4 is set in the determination section 8, an abnormality can be determined by constantly comparing and determining this time with the detected time. By configuring the system to immediately issue a signal from the determination unit 8 and trip the power supply on the next side of the transformer when it is determined that there is an abnormality as a result of the determination, early measures such as inspections can be taken, and serious problems can be prevented. It can be prevented.

Furthermore, when the on-load tap changer and the electric operation mechanism are combined, there are always many mechanical connections between them, but according to this embodiment, these parts can be easily connected. Even when damage occurs, it is possible to detect abnormal operation and stop the switching operation.

Note that the present invention is not limited to the above embodiments,
The detection target may be any operating part that moves in conjunction with the movable contact. For example, if the energy storage mechanism is the detection target,
It has the advantage of being easy to inspect and install on the mountain.

[Effects of the Invention] As explained above, according to the present invention, the operating part of the switching switch can be constantly monitored by the simple configuration of providing a detection part using optical fiber, so that accidents can be detected early before they spread. It is possible to provide a highly reliable on-load tap switching device.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an on-load tap changer showing an embodiment of the present invention, Fig. 2 is a structural diagram showing details of the detection section in the same embodiment, and Fig. 3 is a two-resistance type load FIG. 4 is a switching circuit diagram of the hour tap changer, and FIG. 4 is a switching sequence diagram of the switching circuit of FIG. 3. DESCRIPTION OF SYMBOLS 1...Transformer tank, 2...Insulating tube, 3...Tap selector, 4...Switching switch, 5...Head, 6...
・Detection section, 7... Optical fiber, 8... Judgment section, 9
... Energy storage mechanism, 10... Connecting portion, 11... Fixed contact, 12... Movable contact, 13... Optical fiber, 1
4... Light emitting part, 15... Light receiving part, TW... Tap winding, T+, T2... Movable contact of tap selector, H
A, HB...main contact, WA, WB...resistance contact, R
...Current limiting resistor, S...Movable contact. 7311 Agent Patent Attorney Kensuke Norichika (1 other person)#
1 m TW No. 3111 Fig. 4

Claims (1)

[Scope of Claims] A switching switch that performs a tap switching operation of a transformer tap winding, a tap selector that selects a tap in a tap non-current state of the tap winding, and an electric operating mechanism that drives both. In the on-load tap switching device configured, the operation part of the switching switch is provided with a light emitting part and a light receiving part that receives light from the light emitting part to form a detection part, and the light obtained by the detection part is What is claimed is: 1. An on-load tap switching device, characterized in that a determining section for determining a detected signal is connected thereto.