JPS5867008A - Lead wire connecting device for oil-immersed electric apparatus - Google Patents

Abstract

PURPOSE:To shorten a time duration for field works and to secure insulating reliability of products by eliminating any influence to a serviceable oil-immersed electric apparatus even if any of oil-immersed electric apparatus which is arranged a parallel installation and a parallel connection with other same is separated from the parallel circuit. CONSTITUTION:By applying the same distance between dimensions l1 and l2 which are from the center of diameter of riser ducts 29, 29 on which lead conductors 16, 17 are positioned to the flanges of horizontal member units 30, between dimenisions Lc1 and Lc2 which are from the center of rising ducts 28, 29 to connecting points of lead conductors 17 and 19 further 16 and 18, between dimensions L1 and L2 which are from the center of rising ducts 28, 29 to side ends of external terminals of shield pipes 23, 21, further between dimensions H1 and H2 which are from the center of a common oil duct to the connecting points of lead wire of intermediate terminal boards 10, and between dimensions h1 and h2 which are from the center of the common oil duct to the surface of intermediate terminal boards 10 to be connected to be connected to the riser ducts 28, 29 respectively, repairing work of one of oil-immersed transformer T1 and T2 which are arranged a parallel installation can be conducted without influencing to the other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead wire connection device for oil-filled electrical appliances such as oil-immersed transformers and accelerators, and in particular, connects the high voltage sides of multiple oil-filled electrical appliances in parallel using an oil-immersed junction box. This invention relates to a lead wire connection device for oil-filled electrical appliances.

In recent years, the capacity of transformers installed in mountainous areas has been increasing as the capacity of power plants has increased.

However, the capacity of a single unit is generally limited due to transport size and weight restrictions for power generation and transformation equipment. For this reason, in pumped storage power plants, as shown in Figure 1, an example of a single line diagram,
A No. 1 generator G and a No. 2 generator G are connected in series to the low voltage sides of the No. 1 transformer T1 and No. 2 transformer T2, respectively, and the high voltage sides of the transformers T, T2 are connected in parallel. It is wired and connected to the power transmission line. With this configuration, it is possible to divide the capacity of the generator and transformer into transportable sizes.

The plane cross section of the oil-immersed transformer constructed in this way is shown in FIG. 2, and the vertical cross section is shown in FIG. A transformer 5°6 containing eight windings is housed in a railway 7, and oils 3 and 4 are sealed. The line end of each winding 8 is connected to a high voltage terminal 12 by a main lead wire 13 in a common oil duct 11 via a rising lead wire 14 and an intermediate terminal 10, and a connecting lead wire 15 is connected to a main lead 813. Connected in the middle, two transformers T1. The high voltage side of winding 8 of T2 is connected in parallel. In this example, the illustration of the low voltage side connection to the low voltage terminal 9 is omitted.

In this way, in a structure where multiple oil-immersed transformers installed in parallel are connected in parallel at the high-voltage line end side for operation, if one of the oil-immersed transformers breaks down and requires repair, it is necessary to connect them in parallel. Since you will only be operating transformers that are solved and sound,
Disassembly and reassembly of the lead wires must be accomplished in a short period of time without adversely affecting adjacent oil-immersed transformers.

If one of the oil-immersed transformers installed in parallel, for example oil-immersed transformer T2 in Fig. 3, breaks down, the structure shown in Fig. 10 is generally used to disconnect the parallel circuit.
7. Remove the shield sleeve 25 and rising oil duct 29, cover the open ends of the lead conductor 1B and the shield pipe 23 with a spherical shield 37, and attach the cover 38 to the common oil duct 30. However, if the oil-immersed transformer has ultra-high voltage leads, even if the spherical shield 37 is provided, the dimensions of the common oil duct 30 are already determined, so it is impossible to control the electric field strength at the tip of the spherical shield 37 to below the allowable value. There is a problem with this being possible.

The purpose of the lead wire connection device for oil-filled electrical appliances of the present invention is to enable on-site work without affecting healthy oil-filled electrical appliances even when one of the oil-filled electrical appliances connected in parallel is disconnected from the parallel circuit. The goal is to be able to do this in a short period of time without compromising the insulation reliability of the product.

In order to achieve the above object, the present invention connects the oil tanks of multiple oil-filled electrical appliances arranged side by side via a common oil duct and a riser duct provided with an external terminal at one end, and stores the contents of each oil-filled electrical appliance in the duct. When connecting to an external terminal using a lead wire that leads inside,
The common oil duct is formed by a terminal side unit and a horizontal group unit that is removably connected to the terminal side with a flange. An intermediate terminal board is provided between the oil tank of each oil-filled appliance and the upright side duct to connect the contents of the oil-filled appliance and the leads. The lead wires from the intermediate terminal board to the external terminals are covered with shield pipes and connected in parallel in a common oil duct, and the dimensions between the flanges in horizontal groups from the center of each rising 9 duct and the rising This is characterized in that the distance between the center of the duct q and the connection position of each lead wire in the common oil duct is equal.

Embodiments of the lead wire connecting device of the present invention will be described below with reference to FIGS. 4 to 9.

The rising lead wire 14 includes a lead conductor 32, a shield pipe 20, and an insulator 26. The lead conductor 32 has a thickness that has a cross-sectional area that can thermally withstand the passing current,
Its outer periphery is shielded by a shield pipe 20 and connected to the intermediate terminal board 10. If the lead conductor 32 is directly insulated, the outer diameter of the lead conductor 32 is small, which makes insulation design difficult, especially in the case of ultra-super high voltage equipment where the electric field strength on the surface of the insulator is high. By appropriately setting the outer diameter of the shield pipe 20 and the insulation thickness of the insulator 26, the lead insulator 2
Since the surface electric field strength of 6 can be controlled within a permissible value, it is common to employ a shielded pipe structure in ultra-high voltage transformers.

In order to completely isolate the oil sealed in the oil tanks 1.2 of each transformer T, T2, and to be able to treat the oil in each oil tank 1, 2 independently, the intermediate terminal board 10 is connected to each oil tank 1. .2 and the rising duct 28, 2U. The intermediate terminal plate 10 of the transformer T2 is connected to the high voltage terminal 12 by lead conductors 16, 18 and 19. The intermediate terminal 10 of the transformer T1 is connected to the series lead conductor 19 through a lead conductor 17, so that they are connected in parallel. Lead conductors 16 to 19 are shielded by respective shield pipes 21 to 24 and insulators 27
will be applied. The rising shield pipe 21 and the common shield pipes 23 and 24 are connected to a shield sleeve 25. The shield sleeve 25 is formed into sections in its longitudinal direction as shown in FIG. 5, if necessary. The common shield pipe 23 is provided with a fitting opening 23A for the shield pipe 22, as shown in FIG.

The common oil duct to which an external terminal is attached at one end is formed by removably connecting a terminal side unit 31 and a horizontal group unit 30 with a flange, and these terminal side and horizontal group units 31.3
0 is provided with an opening at a position corresponding to the lead wire connection part in the duct, and a blind cover is normally fixed. The rising ducts 28, 29 from each oil tank 1, 2 are detachably connected to the flanges of the horizontal group unit 30. As shown in FIG. 4, the horizontal group unit 30 includes two oil-immersed transformers T1. When arranging T's in parallel, only one is sufficient, but the number increases by one each time the number of oil-immersed transformers increases.

In the lead wire connection device of the present invention, the lead conductor 16
．． The dimension between t1 and 42 from the radial center of each rising side duct 28°29 where 17 is located to the flange of horizontal group unit 30,
Lead conductors 17 and 1 from the center of the rising duct) 28.29
Dimensions L1 and L2 from the center of 28.29 of 9, 16 and 18 to the external terminal side end of shield pipe 23.21, and dimension H1 from the center of the common oil duct to the lead wire connection point of intermediate terminal board 10. and H2, an intermediate terminal plate 10 to which rising side ducts 28 and 29 are connected from the center of the common oil duct.
The dimensions up to the plane and h2 are equally spaced, so that even when repairing one of the oil-immersed transformers TI and 'T2, which are placed side by side, as will be described later, it can be done without affecting the other. .

Figure 7 shows the state of the oil duct and lead wire when the transformer T near the external terminal is disconnected from the parallel circuit.After applying oil in each duct 28 to 31, remove the rising duct 28, Open the manhole 33 and peel off a part of the insulator 27 to remove the lead conductor 17 and rising shield pipe 22.
After removing the common shield pipe 23, the insertion opening of the common shield pipe 23 is covered with a half-shield sleeve 35 as shown in FIG. 8, and the peeled part of the insulator 27 is re-insulated. Manhole 33 and blind cover 3
By re-lubricating the transformer T2, the transformer T2 can be operated independently. Also, conversely, the transformer T that is far from the external terminal
Figure 9 shows the state of the oil ducts and lead wires when ducts 28 to 31 are connected in parallel as shown in Figure 4. 34 is opened, a part of the insulator 27 is peeled off, and the shield sleeve 25 is removed. Lead conductor 16°1
After disconnecting the oil ducts 28, 29 and 30 and the seal knobs 21, 22 and 28 at the same time, connect the lead conductor 16 of the transformer T2 to the lead conductor F of the transformer T1 as shown in Fig. 9. Instead, it is attached and connected to the common lead conductor 19. Further, a rising shield pipe 21 is attached in place of the rising shield pipe 22, and is connected to the common shield pipe 24 by a shield sleeve 25, so that the peeled portion of the insulator 27 is re-insulated. Start-up side duct 2
9 and apply insulating oil to transformer T1.
can be operated independently.

With this configuration, each oil-immersed transformer can be disconnected from the parallel circuit without draining the oil from the oil-immersed transformers 4, T1 or T2, which are arranged in parallel, and only one transformer can be operated easily. Quick on-site work is possible without compromising insulation reliability.

In the above-described embodiment, an example in which two oil-immersed transformers are installed in parallel has been described, but it is clear that the invention can also be applied to increasing the number of oil-immersed transformers in parallel.

If configured as in the present invention, any one of a plurality of oil-filled electrical appliances connected in parallel through a common oil duct can be easily disconnected from the parallel circuit or reconnected to the parallel circuit without draining the oil in the oil tank. It is possible to maintain high insulation reliability.

[Brief explanation of the drawing]

Figure 1 shows a single-wire connection with two transformers connected in parallel.
Fig. 2 is a cross-sectional view of a transformer with high voltage sides connected in parallel to which the present invention is applied, Fig. 3 is a longitudinal cross-sectional view of Fig. 2, and Fig. 4 is a lead wire connection of an oil-filled electrical appliance of the present invention. FIG. 5 is a perspective view showing the shield sleeve used in FIG. 4, FIG. 6 is a plan view showing the common shield pipe used in FIG. 4, and FIG. A partial vertical sectional view showing the lead wire connection device with the oil-immersed transformer disconnected, FIG. 8 is a perspective view showing the branch shield sleeve used in FIG. 7, and FIG. 9 is the other oil-immersed transformer. FIG. 10 is a partial longitudinal sectional view showing a lead wire connection structure according to the prior art. TI, T2...Oil-immersed transformer, 1, 2...Oil tank, 5,
6...Transformer contents, 10...Intermediate terminal board, 11...
・Common oil duct, 12...external terminal, 13, 14, 1
5... Lead wire, 16.17, 18.19... Lead conductor, 20.21, 22, 23.24... Shield pipe, 25.35... Shield sleeve, 26.2
7...Insulator, 28.29...Rising duct, 31
...Terminal side Fig. 3 0 Fig. 5 Fig. 6

Claims (1)

[Scope of Claims] 1. A plurality of oil-filled electrical appliances each storing the contents of the oil-filled electrical appliances in an oil tank are arranged side by side, each of the oil tanks is connected to a common oil duct via a riser duct, and one end of the common oil duct is connected to a common oil duct. In a device that connects the external terminal provided on the side and the contents of each oil-filled electrical appliance using a lead wire that leads inside the duct. The common oil duct is formed by a terminal side unit and a horizontal group unit which is detachably connected to the terminal side unit by seven lunges, and an intermediate terminal plate is provided at the joint between each rising duct connected to the horizontal group unit and each oil tank. , connect the lead wire from the contents of the oil-filled appliance to the oil tank side of the intermediate terminal board, connect the lead wire covered by a shield pipe to the common oil duct side of the intermediate terminal board, and connect each lead wire to the common oil duct side. Connected in parallel in the oil duct and connected to external terminals, dimensions from the center of each rising duct to the flanges in horizontal group units, and dimensions from the center of the rising duct to the connection position of each lead wire in the common oil duct. A lead wire connection device for an oil-filled electrical appliance, characterized in that: