JPS59126616A - Resistance-type on-load tap changer - Google Patents

Abstract

PURPOSE:To release an electric field around a change-over switch and reduce the total dimensions by providing a cylindrical potential shielding board on the circumference of an oil bath insulation cylinder. CONSTITUTION:An oil bath insultion cylinder 13 is provided in a transformer tank 1 and a change-over switch is housed in this insulation cylinder 13. In the resistance-type on-load tap changer thus composed, a potential shielding board 18 is provided outside the insulation cylinder 13 and its potential is kept equal to that of the change-over switch. With this constitution, an electric field around the change-over switch, which has a complex shape and many metallic protrusions, is made cylindrical and stable. Therefore, insulation distance between the switch and the tank wall or the core surface can be significantly reduced and the total dimensions of the transformer ca be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a double-load tag cutter (two switches, one switch opener) and an oil clearing structure of the i-1 switch section.

[Technical background of the invention and seven problems]

The on-load tap changer has a rotary operation transmitted from the electric operating mechanism, a drive and a table that transmits the rotational movement to the moving shaft in the on-load tag changer, and the Wr device.

It consists of a switching switch part consisting of a current limiting resistor kt, etc., and a switching part containing 5] sea bream contacts, fixed contacts, etc.

Since the switching switch part frequently interrupts the current, the insulating oil decomposes due to arcing, carbon is generated, and the insulating oil deteriorates.

We also investigated the state of wear on the current-carrying contacts, and depending on the state of wear, it may be necessary to replace the entire device.

These operations must be performed without draining the insulating oil in the transformer main body, so the switching switch section is completely connected to the transformer main body oil (two independent oil tanks).

FIG. 1 is a diagram showing the relationship between a resistive on-load tap changer of conventional structure and a transformer body.

The on-load tap changer is housed in the transformer tank 1 together with the core 2 and winding @i3 of the transformer body.

The electric operating mechanism 5 receives a step-up or step-down signal from an externally installed control panel due to fluctuations in power supply voltage or changes in load (2). (The two drive units have seven areas and two transmissions.

As mentioned above, the on-load tap changer consists of a switching switch part consisting of a drive device 7, an energy storage device 8, a current cutoff device 9, a current limiting resistor 10, etc., and a tap lead drawn out from the transformer coil 3. It is composed of a fixed terminal 11 for connecting the terminals 4 and a switching section consisting of a movable contact 12 and the like.

The switching switch part consists of an insulating cylinder 13, a head cover 14, and an oil tank lower frame 15 (two independent oil tanks).

In addition, the outside of the oil tank insulating tube 13 of the on-load tap changer which requires a high pressure changer (- indicates the charging side shield ring 16 connected to the loading unit and the head cover (2) the grounded shield ring 1
7 to ensure insulation.

(In the - case, the switch part is connected to the fixed terminal 11, and in the - position, the switch part is surrounded by the tap lead 4, which is at the same level as the Y, and is electrically shielded, but in the - case, the switch part is connected to the d closed part. Because it directly opposes the wall of tank 1 or the side of iron core 2, an electrical shield cannot be expected.For this reason, a tap changer for line end switching at load, etc., which can switch back the tap by controlling voltage, is installed in a nearby tank. Keep a sufficient distance from the wall in 1 and the 91 structure in 2 to ensure insulation.

Moreover, the energy storage device 8, the current cutoff device 9, etc. have complicated shapes, so that electric field concentration occurs.

For this reason, conventional resistance-type load tap changers require a large insulation gap in the oil tank insulating cylinder 13 (2) around the stored changeover switch (2), so the tank size is small, the amount of insulating oil, the transformer Weight, @ space, etc. will increase, and shipping will be delayed (
Two is also a hindrance.

[Purpose of the invention]

It is an object of the present invention to solve these problems and to provide a resistive on-load tap cutter which is advantageous in terms of cost by making the entire transformer more compact.

[Summary of the invention]

Transformer tank or on-load tag changer tank (double digit resistance type on-load tap changer (2) The outer periphery of the oil tank tank section that houses the changeover switch and separates it from the insulating oil of the transformer body (1) A resistive load tap change transformer characterized by having a potential shield plate arranged.

[Embodiments of the invention]

The present invention will be explained below with reference to an embodiment shown in FIG.

The same parts as in FIG. 1 showing the conventional structure are given the same reference numerals. A potential shield plate 18 is disposed outside the oil tank insulator 13 that houses the switching switch part, and the oil tank insulator 18 is installed with an electric potential shield plate 18.
Fix f2. Here, the potential shield plate 13 is set to the FA switchgear potential.

The potential shield plate 18 is flexible and flexible, so it can be easily attached.

FIG. 3 shows a modified example i of FIG. 2, in which a part of the oil tank insulating cylinder 13 in the cut-off switching switch portion is replaced with the old tank 19, and the young fruits are swallowed as in FIG. 2.

[Young fruit of Genmei]

This structure is fibrous in shape and has numerous protrusions.
The area around the cut-back switch becomes a stable cylindrical enclosure, allowing the insulation distance from the tank ship and the iron core to be significantly reduced.

Therefore, the tank was made smaller, the loquat oil filter was installed, and the transformer was installed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the relationship between a conventional on-load tap changer and a transformer body, and FIG. 2 is a main part of an embodiment of the resistive on-load tap changer of the present invention. FIG. 3 is a cross-sectional view showing a modification of FIG. 2. l...Transformer tank 2...Iron core 3...Winding
4...Tap lead 5...Electric motor f[mechanism 6...*Driving shaft 7...Drive device 8...
- Energy storage device 9... Current-carrying Kr steel straight 10... Current limiting resistor 11... Fixed terminal 12... Possible a terminal 1
3... Insulating cylinder 16... Grain side shield ring 17... Grounding ring] Shield ring 18... - position shield plate 19... Metal oil sliding part

Claims (1)

[Claims] The transformer tank or on-load tap changer tank (2) There is a cylindrical tank on the outer periphery of the insulating cylindrical part that houses the changeover switch and separates it from the insulating oil of the transformer body. A resistive load tap changer characterized by a potential shield plate.