JP4280040B2 - On-load tap change transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a load tap change transformer including a load tap changer and a conservator.
[0002]
[Prior art]
The on-load tap change transformer is a transformer provided with a load tap changer that switches the tap of the transformer in a state where the load is connected to the transformer.
[0003]
In the load-tap switching transformer, the expansion and contraction of the insulating oil in the transformer tank and in the switching switch housing chamber caused by the heat generated from the switching body of the transformer main body and the load tap switch and the change in ambient temperature. In order to absorb, a conservator is provided in each of the transformer tank and the switching switch accommodating chamber.
[0004]
The on-load tap changer includes a tap selector that selects the tap of the winding of the transformer and an oil-in-oil switch type switching switch that opens and closes the load current when the tap of the winding is switched. This switching switch is accommodated in the switching switch accommodating chamber filled with insulating oil filled in the transformer tank and isolated from the insulating oil, and is accommodated in the transformer tank together with the transformer body. The on-load tap changer is driven via a transmission mechanism by an electric operation mechanism (not shown) provided outside the transformer tank.
[0005]
FIG. 2 shows such a conventional on-load tap change transformer. In FIG. 2, reference numeral 1 denotes a transformer tank. The transformer tank 1 is filled with an insulating oil 2, and a switching body in which a transformer body 3 having a tap in a winding and a switching switch 12 is accommodated. An on-load tap changer 9 having a storage chamber 11 is accommodated. Further, a first conservator 6 for the transformer tank 1 and a second conservator 16 for the switching switch accommodating chamber 11 are arranged above the transformer tank 1 and transformed by a support base (not shown). It is supported on the upper part of the vessel tank 1.
[0006]
In the above-described tap change-over transformer, the insulating oil 2 in the transformer tank 1 and the insulating oil 2a in the switching switch accommodating chamber 11 are isolated from each other, thereby generating in the switching switch 12 when the winding tap is switched. The cracked gas generated from the insulating oil 2a by the arc prevents the insulating oil 2 in the transformer tank 1 from being contaminated.
[0007]
The on-load tap changer 9 is inserted into the transformer tank 1 through an opening provided in the ceiling of the transformer tank 1, and the opening of the ceiling of the transformer tank 1 is liquid-tightly closed.
[0008]
The first conservator 6 is connected to the upper part of the transformer tank 1 through the connecting pipe 5, and the same insulating oil as the insulating oil 2 filled in the transformer tank 1 is a predetermined oil of the first conservator 6. It is accommodated up to the surface level position (L1). A protective relay 4 is provided in the middle of the connecting pipe 5.
[0009]
One end of an inverted J-shaped breathing tube 7 is connected to the upper part of the first conservator 6, and a hygroscopic respirator 8 is connected to the other end (lower end) of the breathing tube 7.
[0010]
The second conservator 16 is connected to the upper part of the switching switch accommodating chamber 11 through the connecting pipe 15, and the same insulating oil as the insulating oil 2 a filled in the switching switch accommodating chamber 11 is supplied to the second conservator 16. To a predetermined oil level level (L2). A protective relay 14 is provided in the middle of the connecting pipe 15.
[0011]
One end of a respiratory tube 17 formed in an inverted J shape is connected to the upper part of the second conservator 16, and a hygroscopic respirator 18 is connected to the other end of the respiratory tube 17.
[0012]
In the above-described tap switching transformer at the time of loading, the expansion of the insulating oil 2 in the transformer tank 1 and the insulating oil 2a in the switching switch accommodating chamber 11 causes the expansion and contraction of the first conservator 6 and the second con- verter. The oil level of the insulating oil in the beta 16 changes, and breathing is performed through the hygroscopic respirators 8 and 18 in accordance with the change in the oil level. The hygroscopic respirators 8 and 18 circulate air through the hygroscopic agent, and are provided to prevent moisture in the atmosphere from entering the first conservator 6 and the second conservator 16. Yes.
[0013]
In the on-load tap change transformer shown in FIG. 2, the oil level level position (L1) of the first conservator 6 is set in order to make the pressure in the transformer tank 1 and the changeover switch accommodating chamber 11 the same. ) And the oil level level position (L2) of the second conservator 16 are determined so that the heights of the support bases (not shown) of both conservators are determined.
[0014]
[Problems to be solved by the invention]
In the conventional on-load tap change transformer shown in FIG. 2, since the conservators 6 and 16 are provided, the number of parts related to the conservator and the conservator increases, the material cost increases, and There is a problem that the number of assembly steps increases because it must be incorporated. Further, since the oil level level position (L1) of the first conservator 6 and the oil level level position (L2) of the second conservator 16 are determined by the respective oil temperatures, the respective oil level levels are always matched. The pressure difference is generated between the transformer tank 1 and the switching switch accommodating chamber 11 and a differential pressure is generated. The seal portion of the switching switch accommodating chamber 11 is burdened by this differential pressure, and the sealing function. There was also a problem of speeding up the decline.
[0015]
SUMMARY OF THE INVENTION An object of the present invention is to provide a load tap switching transformer that does not increase the number of parts related to the conservator and the conservator, and does not accelerate the deterioration of the sealing function of the seal portion of the switching switch housing chamber. is there.
[0016]
[Means for Solving the Problems]
The invention according to claim 1 includes a transformer main body and a load tap changer, a transformer tank in which the load tap changer is accommodated together with the transformer main body and filled with insulating oil, and the transformer tank And a switching switch accommodating chamber of the on-load tap changer filled with isolated insulating oil, and the switching switch accommodated in the switching switch accommodating chamber is a A vacuum valve isolated from the insulating oil is provided, and the transformer tank and the switching switch accommodating chamber are connected to a common conservator through a connecting pipe provided in each.
In the invention of claim 1, the number of conservators and the number of parts related to conservators can be reduced, and the material cost and the number of assembling steps can be reduced. In addition, there is no pressure difference between the transformer tank and the switching switch housing chamber, and the differential pressure is eliminated. The load on the seal portion of the switching switch housing chamber due to this differential pressure is eliminated, and the deterioration of the sealing function is not accelerated.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the on-load tap switching transformer according to the present invention. In FIG. 1, the same parts as those of the conventional on-load tap switching transformer shown in FIG. The same reference numerals as those in FIG.
[0018]
In FIG. 1, reference numeral 1 denotes a transformer tank. The transformer tank 1 is filled with insulating oil 2 to open and close a transformer body 3 having a tap on the winding and a load current when the tap of the winding is switched. The on-load tap changer 9 including the changeover switch accommodation chamber 11 in which the changeover switch 22 is accommodated is accommodated. Further, a conservator 19 shared by the transformer tank 1 and the switching switch accommodating chamber 11 is disposed above the transformer tank 1, and is supported on the upper portion of the transformer tank 1 by a support base (not shown).
[0019]
The on-load tap changer 9 is inserted into the transformer tank 1 through an opening provided in the ceiling of the transformer tank 1, and the opening of the ceiling of the transformer tank 1 is liquid-tightly closed.
[0020]
The switching switch 22 is provided with a vacuum valve configured to be isolated from the insulating oil 2 in the switching switch housing chamber 11.
[0021]
The conservator 19 is connected to the upper part of the transformer tank 1 through the connecting pipe 5, and further connected to the upper part of the switching switch accommodating chamber 11 through the connecting pipe 15, and the insulating oil 2 filled in the transformer tank 1 The same insulating oil is accommodated up to a predetermined oil level level position (L1) of the conservator 19. Further, protective relays 4 and 14 are provided in the middle of the connecting pipes 5 and 15, and a gate valve 13 is provided in the middle of the connecting pipe 15.
[0022]
One end of a breathing tube 20 formed in an inverted J shape is connected to the upper part of the conservator 19, and a hygroscopic breathing device 21 is connected to the other end (lower end) of the breathing tube 20.
[0023]
In the on-load tap change transformer described above, the oil level of the insulating oil 2 in the conservator 19 is increased as the insulating oil 2 in the transformer tank 1 and the insulating oil 2 in the switching switch accommodating chamber 11 expand and contract. As the oil level changes, breathing is performed through the hygroscopic respirator 21. The hygroscopic respirator 21 circulates air through the hygroscopic agent, and is provided to prevent moisture in the atmosphere from entering the conservator 19. In addition, when the switching switch 22 needs to be inspected, the gate valve 13 that is open is closed during operation to enable the hanging inspection work.
[0024]
In the on-load tap switching transformer, the switching switch 22 is provided with a vacuum valve, so that when the conventional switching switch 12 is used, the insulating oil 2a contaminated by the arc is passed through the conservator 19. Outflow to the transformer tank 1 can be prevented.
[0025]
Moreover, if the conservator 19 is shared, the number of parts related to the conservator and the conservator can be reduced, and the material cost and assembly man-hour can be reduced. Furthermore, there is no pressure difference between the transformer tank 1 and the switching switch accommodating chamber 11 and there is no differential pressure, and the burden on the seal portion of the switching switch accommodating chamber 11 due to this differential pressure is eliminated, thereby deteriorating the sealing function. There is nothing.
[0026]
【The invention's effect】
As described above, according to the first aspect of the present invention, the transformer tank is provided with the transformer main body and the on-load tap changer, and the on-load tap changer is accommodated together with the transformer main body and filled with insulating oil. And a switching switch accommodating chamber of the load tap changer filled with insulating oil filled in the transformer tank and isolated insulating oil, and the switching switch accommodated in the switching switch accommodating chamber is: With a vacuum valve isolated from the insulating oil in the switching switch housing chamber, the transformer tank and the switching switch housing chamber are connected to a common conservator through a connecting pipe provided in each, The number of conservators and conservator-related parts can be reduced, and material costs and assembly man-hours can be reduced. Furthermore, there is no pressure difference between the transformer tank and the switchgear accommodating chamber, the pressure difference is eliminated, the burden on the seal portion of the switchgear accommodating chamber due to this differential pressure is eliminated, and the deterioration of the sealing function is not accelerated.
[Brief description of the drawings]
FIG. 1 is a front cross-sectional view showing a state in which a part of a load tap change transformer according to the present invention is cut.
FIG. 2 is a front sectional view showing a state in which a part of a conventional on-load tap switching transformer is cut.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transformer tank 2, 2a Insulation oil 3 Transformer main body 4,14 Protection relay 5,15 Connection pipe 6 1st conservator 7,17,20 Breathing pipe 8,18,21 Hygroscopic breathing machine 9 Tap changer at load 11 switching switch accommodating chambers 12, 22 switching switch 13 gate valve 16 second conservator 19 conservators L1, L2 oil level level position

Claims (1)

A transformer main body and a load tap changer; a transformer tank in which the load tap changer is housed together with the transformer main body and filled with insulating oil; and an insulating oil filled in the transformer tank And a load tap change transformer comprising a load change switch accommodation chamber of the load tap changer filled with insulating oil isolated from
The switching switch housed in the switching switch housing chamber includes a vacuum valve isolated from the insulating oil in the switching switch housing chamber, and the transformer tank and the switching switch housing chamber are provided respectively. A tap change transformer at the time of loading, which is connected to a common conservator through a connected pipe.

Images