EP0150132A2 - On-load tap changer - Google Patents
On-load tap changer Download PDFInfo
- Publication number
- EP0150132A2 EP0150132A2 EP85300443A EP85300443A EP0150132A2 EP 0150132 A2 EP0150132 A2 EP 0150132A2 EP 85300443 A EP85300443 A EP 85300443A EP 85300443 A EP85300443 A EP 85300443A EP 0150132 A2 EP0150132 A2 EP 0150132A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- vessel
- conduit
- oil
- tap changer
- switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/08—Cooling; Ventilating
- H01F27/10—Liquid cooling
- H01F27/12—Oil cooling
- H01F27/14—Expansion chambers; Oil conservators; Gas cushions; Arrangements for purifying, drying, or filling
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F29/00—Variable transformers or inductances not covered by group H01F21/00
- H01F29/02—Variable transformers or inductances not covered by group H01F21/00 with tappings on coil or winding; with provision for rearrangement or interconnection of windings
- H01F29/025—Constructional details of transformers or reactors with tapping on coil or windings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/0005—Tap change devices
- H01H2009/0055—Oil filters for tap change devices
Definitions
- This invention relates to an on-load tap changer, and more particularly, to an oil-cleaning system for an oil-filled on-load tap changer.
- a diverter switch of a conventional on-load tap changer is basically a switch for switching a load current of a transformer to a preselected tap by the tap selector at zero current.
- the diverter switch is enclosed within a vessel filled with an electrically insulating oil.
- the insulating oil is gradually polluted and degraded as it is decomposed to form foreign materials such as carbon and sludge by the electric arcing upon each tap change, thereby degrading the electrically insulating properties.
- the on-load tap changer for use with a high-voltage transformer is provided with an hot-line oil filter, which is a kind of a filter with a pump in it, and the insulating oil is filtered through the oil filter once a day as is well known in the art.
- the conduit connecting the vessel for the diverter switch and the oil filter is arranged such that polluted oil at the bottom of the vessel of the tap-changer is suctioned into the conduit and pumped through the oil filter of the oil filter to return to the upper portion of the tap changer vessel.
- the tap changer is typically suspended from the top of the transformer tank, and the oil filter is positioned outside the transformer tank and is placed on the same level as the bottom of the transformer tank.
- the suction conduit from which the oil enters for cleaning is typically constructed and incorporated as one of the parts of the tap changer, the conduit rises from the bottom portion of the vessel and extends outwardly through the upper portion of the vessel which is secured to the upper tank of the transformer.
- the vessel is suspended from the top plate of the transformer tank, the vessel is usually positioned at a level which is higher than that of the oil filter.
- the conventional on-load tap changer thus constructed has the following disadvantageous characteristics.
- an object of the present invention is to provide an on-load tap changer which is free from the above-mentioned drawback.
- Another object of the present invention is to provide an on-load tap changer in which there is no risk of most of electrically insulating oil flowing out from the tap changer system.
- a further object of the present invention is to provide an on-load tap changer in which there is no risk of the level of insulating oil falling due to an oil leak and the interrupting unit of the tap changer being exposed.
- an on-load tap changer of the present invention comprises a switch including an arc interrupting unit, a vessel containing the switch, an electrically insulating oil disposed within the vessel for electrically insulating the switch, and a closed oil passage loop for circulating the insulating oil therealong.
- the loop includes a conduit having an inlet at the bottom portion of the interior of the vessel.
- the conduit upwardly extends inside of the vessel and exits from the upper portion of the vessel, extends through a position lower than the vessel, and connects to an upper portion of the vessel, the conduit having formed therein a hole at a position higher than the arc interrupting unit, the hole being positioned inside of the vessel.
- a float valve is provided in the vessel for closing the hole in the conduit when the level of the insulating oil within the vessel is at or higher than the hole and opening the hole when the reveal of the insulating oil within the vessel is lower than the hole.
- a closed oil passage loop in another embodiment, includes a first conduit which has an inlet at the bottom portion of the interior of the vessel, and which upwardly extends outside of the vessel and exits from a position higher than the arc interrupting unit and extends to a position lower than the vessel, and a second conduit connected to the first conduit to return the insulating oil to an upper portion of the vessel, and a small-diameter pipe connecting the first conduit at a position higher than the arc interrupting unit to the second conduit.
- the small-diameter pipe has an inside diameter sufficiently smaller than the inner diameter of the first conduit to permit most of the insulating oil supplied into the oil filter to be supplied from the inlet of the conduit at the bottom portion of the vessel rather than the upper portion of the vessel.
- FIG. 1 An on-load tap changer 10 of the present invention is illustrated in Fig. 1 as being incorporated into an electrical power transformer 12 having a hermetic housing 14.
- the tap changer 10 comprises a hermetic vessel 16 within which a diverter switch 18 and an arc interrupter unit 20 are enclosed.
- the vessel 16 has an upper portion 22 and a lower portion 24 in communication with each other.
- the upper portion 22 of the vessel 16 is placed on the top plate 15 of the transformer housing 14 and the lower portion 24 of the vessel 16 is suspended into the interior of the transformer housing 14.
- the diverter switch 18 and the arc interrupting unit 20 are disposed within the lower portion 24 of the vessel 16. Therefore they are positioned within the transformer housing 14, but are isolated by the wall of the vessel 16 from the interior of the transformer housing 14.
- the tap changer vessel 16 is substantially filled with an electrically insulating oil 26 in order to promote the quick extinction of the arc generated during tap changing.
- a conservater 28 connected to a breazer 30 by a conduit 32 is connected to the upper portion 22 of the tap-changer vessel 16 through a conduit 34.
- the tap changer 10 also comprises an oil filter 36 which includes a pump and a filter. It is seen that the bottom wall of the oil filter 36 is positioned at the same level as the bottom wall of the transformer housing 14 and therefore the oil filter 36 is positioned lower than the tap changer 10 which is positioned at the upper portion of the transformer housing 14.
- the inlet of the oil filter 36 is connected to the bottom portion of the tap changer vessel 16 by a first conduit 38 having an inlet 40 at the bottom portion inside the tap changer vessel 16.
- the first conduit 38 has the shape of an inverted "U". This is because the tap changer 10 is typically designed as an assembled unit with at least part of the conduit 38 incorporated into the vessel 16 and it is not desirable to design the walls of the vessel 16 and the transformer housing 14 to be penetrated by the conduit 38.
- the outlet of the oil filter 36 is connected to the upper portion 22 of the tap changer vessel 16 through a second conduit 42.
- a closed oil passage loop 43 composed of the vessel 16, the inverted-U shaped conduit 38, the oil filter 36, and the second conduit 42 is formed.
- the inverted U-shaped conduit 38 has formed therein an air breezing hole 44 at its top portion.
- the hole 44 communicates the inside of the conduit 38 to the interior of the upper portion 22 of the tap changer vessel 16.
- the hole 44 can be closed by a float valve 46 comprising a valve 48 for fluid-tightly closing the hole 44, a rocking lever 50 carrying the valve 48 at its one end and pivotally supported at midpoint 52, and a float 54 supported on the other end of the lever 50.
- the float valve 46 is closed by the counterclockwise rotational moment on the lever 50 due to the buoyancy of the float 54 when the oil level is higher than a predetermined level, and is opened by the clockwise rotational moment due to the greater weight of the float 54.
- the pump (not shown) in the oil filter 36 is energized to suction the insulating oil 26 in the bottom portion of the tap changer vessel 16 from the inlet 40.
- the buoyancy of the float 54 presses the valve 48 against the hole 44. Therefore, the insulating oil 26 is supplied into the oil filter 36 only from the inlet 40 at the bottom of the tap changer vessel 16 and no oil passes through the hole 44.
- the oil 26 supplied through the conduit 38 to the oil filter 36 passes through the filter (not shown) of the oil filter 36 to be cleaned.
- the filtered oil 26 is returned to the upper portion 22 of the vessel 16 and descend to the bottom portion of the vessel 16.
- the insulating oil 26 recirculates through the closed oil passage loop 43 composed of the vessel 16, the inverted U-shaped conduit 38, the oil filter 36, the conduit 42 and again the vessel 16.
- the pump is deenergized.
- the insulating oil 26 within the tap changer vessel 16 flows out from the inlet 40 of the conduit 38 through the conduit 38 and from the leak in the oil filter 36.
- the insulating oil 26 empties first from the conservator 28, and then the level of the insulating oil 26 within the upper portion 22 of the tap changer vessel 16 gradually descends. This gradual descending of the oil level causes the float 54 to also gradually descend due to gravity and when the oil level in the upper portion 22 of the tap changer vessel 16 reaches the hole 44 in the conduit 36, the float 54 cannot provide any force to press the valve 48 against the hole 44, thereby opening the air breazing hole 44 in the first conduit 38.
- the air introduced within the vessel 16 from the breazer 30 flows into the small hole 44 to prevent the further lowering of the oil level in the tap changer vessel 16 because the insulating oil 26 in the upper portion 22 and the lower portion 24 of the vessel 16 is trapped in the vessel 16.
- the oil 26 within the section of the conduit 38 to the left of the small hole 44 and the oil in the oil filter 36 flows out through the leak in the filter 36. Therefore, even when an oil leak occurs in the oil filter 36, the insulating oil 26 around the arc interrupting unit 20 in the vessel is maintained.
- the oil conduit has formed therein an air breazing hole at a position higher than the interrupting unit, and the hole can be opened by a float valve only when the insulating oil in the vessel is reduced to lower than the level of the hole in the conduit. Therefore, the insulating oil cannot be emptied from the tap changer vessel, thus preventing accidents such as short-circuiting among taps.
- Fig. 2 illustrates another embodiment of the present invention, in which a closed oil passage loop 56 of this embodiment is different from the embodiment shown in Fig. 1 in that an inverted-U shaped first conduit 58 shown in Fig. 2 extends outside of the tap changer vessel 16 without passing through the upper portion 22 of the vessel 16.
- the first conduit 58 has an inlet 60 in the bottom portion of the wall of the vessel 16 and extends through the top plate 19 of the tap changer 10.
- the first conduit 58 is communicated at a position higher than the interrupting unit of the tap changer through a flow resistance pipe 62 with a second conduit 64 having an outlet 65 connecting the oil filter 36 to the upper portion 22 of the vessel 16.
- the pipe 62 is designed to exhibit a very high flow resistance against the insulating oil 26 flowing therethrough as compared to the flow resistance in the section of the conduit 58 between the inlet 60 and the pipe 62.
- the pipe 62 has a very small inner diameter compared to the inside diameter of the conduit 58.
- the flow resistance of the small pipe 62 is very high compared to the flow resistance of the flow path in the conduit 58 through the inlet 60. Therefore, most of the insulating oil 26 supplied into the oil filter 36 is supplied from the inlet 60 at the bottom of the tap changer vessel 16 rather than from the upper portion 22 of the vessel 16 through the pipe 62 connected to the outlet end of the second conduit 64.
- the oil 26 supplied through the conduit 58 to the oil filter 36 passes through the filter (not shown) of the oil filter 36 to be cleaned.
- the filtered oil 26 is returned through the second conduit 64 to the upper portion 22 of the vessel 16 and descends to the bottom portion of the vessel 16.
- the insulating oil 26 recirculates through a closed oil passage loop 56 composed of the vessel 16, the first conduit 58, the oil filter 36, and the second conduit 64.
- the present invention has been described in terms of a tap changer of a particular type, the invention may be equally applicable to on-load tap changer of other types such as a tap selector switch which has the functions of both a tap selector and a diverter switch.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Transformer Cooling (AREA)
- Housings And Mounting Of Transformers (AREA)
Abstract
Description
- This invention relates to an on-load tap changer, and more particularly, to an oil-cleaning system for an oil-filled on-load tap changer.
- A diverter switch of a conventional on-load tap changer is basically a switch for switching a load current of a transformer to a preselected tap by the tap selector at zero current. In order to facilitate the extinguishing of an electric arc generated at the time of current commutation, the diverter switch is enclosed within a vessel filled with an electrically insulating oil. The insulating oil is gradually polluted and degraded as it is decomposed to form foreign materials such as carbon and sludge by the electric arcing upon each tap change, thereby degrading the electrically insulating properties. Therefore, the on-load tap changer for use with a high-voltage transformer is provided with an hot-line oil filter, which is a kind of a filter with a pump in it, and the insulating oil is filtered through the oil filter once a day as is well known in the art.
- The conduit connecting the vessel for the diverter switch and the oil filter is arranged such that polluted oil at the bottom of the vessel of the tap-changer is suctioned into the conduit and pumped through the oil filter of the oil filter to return to the upper portion of the tap changer vessel. Since the tap changer is typically suspended from the top of the transformer tank, and the oil filter is positioned outside the transformer tank and is placed on the same level as the bottom of the transformer tank. Also, since the suction conduit from which the oil enters for cleaning is typically constructed and incorporated as one of the parts of the tap changer, the conduit rises from the bottom portion of the vessel and extends outwardly through the upper portion of the vessel which is secured to the upper tank of the transformer. Furthermore, since the vessel is suspended from the top plate of the transformer tank, the vessel is usually positioned at a level which is higher than that of the oil filter.
- The conventional on-load tap changer thus constructed has the following disadvantageous characteristics.
- When insulating oil leaks from the filter or the pump of the oil filter, the insulating oil within the conduits and the vessel flows out through the leak and the oil level within the vessel falls. This lowering of the insulating oil continues until the oil level reaches the level at the inlet of the suction conduit because the conduit has an inverted U-shape which causes the U-shaped conduit to function as a siphon conduit. Therefore, the oil leakage from the oil filter may cause most of the insulating oil within the tap-changer vessel to flow outside of the system. If the oil level becomes lower than the interrupting unit, then the arcs will not be extinguished, leading to short-circuits between the taps.
- Accordingly, an object of the present invention is to provide an on-load tap changer which is free from the above-mentioned drawback.
- Another object of the present invention is to provide an on-load tap changer in which there is no risk of most of electrically insulating oil flowing out from the tap changer system.
- A further object of the present invention is to provide an on-load tap changer in which there is no risk of the level of insulating oil falling due to an oil leak and the interrupting unit of the tap changer being exposed.
- With the above objects in view, an on-load tap changer of the present invention comprises a switch including an arc interrupting unit, a vessel containing the switch, an electrically insulating oil disposed within the vessel for electrically insulating the switch, and a closed oil passage loop for circulating the insulating oil therealong. The loop includes a conduit having an inlet at the bottom portion of the interior of the vessel. The conduit upwardly extends inside of the vessel and exits from the upper portion of the vessel, extends through a position lower than the vessel, and connects to an upper portion of the vessel, the conduit having formed therein a hole at a position higher than the arc interrupting unit, the hole being positioned inside of the vessel. A float valve is provided in the vessel for closing the hole in the conduit when the level of the insulating oil within the vessel is at or higher than the hole and opening the hole when the revel of the insulating oil within the vessel is lower than the hole.
- In another embodiment of the present invention, a closed oil passage loop includes a first conduit which has an inlet at the bottom portion of the interior of the vessel, and which upwardly extends outside of the vessel and exits from a position higher than the arc interrupting unit and extends to a position lower than the vessel, and a second conduit connected to the first conduit to return the insulating oil to an upper portion of the vessel, and a small-diameter pipe connecting the first conduit at a position higher than the arc interrupting unit to the second conduit. The small-diameter pipe has an inside diameter sufficiently smaller than the inner diameter of the first conduit to permit most of the insulating oil supplied into the oil filter to be supplied from the inlet of the conduit at the bottom portion of the vessel rather than the upper portion of the vessel.
- The invention will become more readily apparent from the following detailed description of the preferred embodiment of the present invention taken in conjunction with the accompanying drawings, in which:
- Fig. 1 is a diagramatic view of an on-load tap changer constructed in accordance with the present invention; and
- Fig. 2 is a diagramatic view of an on-load tap changer of another embodiment of the present invention.
- An on-
load tap changer 10 of the present invention is illustrated in Fig. 1 as being incorporated into anelectrical power transformer 12 having ahermetic housing 14. Thetap changer 10 comprises ahermetic vessel 16 within which adiverter switch 18 and anarc interrupter unit 20 are enclosed. Thevessel 16 has anupper portion 22 and alower portion 24 in communication with each other. Theupper portion 22 of thevessel 16 is placed on thetop plate 15 of thetransformer housing 14 and thelower portion 24 of thevessel 16 is suspended into the interior of thetransformer housing 14. Thediverter switch 18 and thearc interrupting unit 20 are disposed within thelower portion 24 of thevessel 16. Therefore they are positioned within thetransformer housing 14, but are isolated by the wall of thevessel 16 from the interior of thetransformer housing 14. - The
tap changer vessel 16 is substantially filled with an electrically insulatingoil 26 in order to promote the quick extinction of the arc generated during tap changing. In order to absorb the volumetric expansion of the insulatingoil 26 due to temperature changes, aconservater 28 connected to abreazer 30 by aconduit 32 is connected to theupper portion 22 of the tap-changer vessel 16 through aconduit 34. Thetap changer 10 also comprises anoil filter 36 which includes a pump and a filter. It is seen that the bottom wall of theoil filter 36 is positioned at the same level as the bottom wall of thetransformer housing 14 and therefore theoil filter 36 is positioned lower than thetap changer 10 which is positioned at the upper portion of thetransformer housing 14. - The inlet of the
oil filter 36 is connected to the bottom portion of thetap changer vessel 16 by afirst conduit 38 having aninlet 40 at the bottom portion inside thetap changer vessel 16. Thefirst conduit 38 has the shape of an inverted "U". This is because thetap changer 10 is typically designed as an assembled unit with at least part of theconduit 38 incorporated into thevessel 16 and it is not desirable to design the walls of thevessel 16 and thetransformer housing 14 to be penetrated by theconduit 38. The outlet of theoil filter 36 is connected to theupper portion 22 of thetap changer vessel 16 through asecond conduit 42. Thus, a closedoil passage loop 43 composed of thevessel 16, the inverted-U shapedconduit 38, theoil filter 36, and thesecond conduit 42 is formed. - According to the present invention, the inverted
U-shaped conduit 38 has formed therein anair breezing hole 44 at its top portion. Thehole 44 communicates the inside of theconduit 38 to the interior of theupper portion 22 of thetap changer vessel 16. Thehole 44 can be closed by afloat valve 46 comprising avalve 48 for fluid-tightly closing thehole 44, a rockinglever 50 carrying thevalve 48 at its one end and pivotally supported atmidpoint 52, and afloat 54 supported on the other end of thelever 50. Thefloat valve 46 is closed by the counterclockwise rotational moment on thelever 50 due to the buoyancy of thefloat 54 when the oil level is higher than a predetermined level, and is opened by the clockwise rotational moment due to the greater weight of thefloat 54. - In order to clean the insulating
oil 26 of thetap changer 10, the pump (not shown) in theoil filter 36 is energized to suction the insulatingoil 26 in the bottom portion of thetap changer vessel 16 from theinlet 40. It is to be noted that when the insulatingoil 26 fills theupper portion 22 of thevessel 16, the buoyancy of thefloat 54 presses thevalve 48 against thehole 44. Therefore, the insulatingoil 26 is supplied into theoil filter 36 only from theinlet 40 at the bottom of thetap changer vessel 16 and no oil passes through thehole 44. Theoil 26 supplied through theconduit 38 to theoil filter 36 passes through the filter (not shown) of theoil filter 36 to be cleaned. The filteredoil 26 is returned to theupper portion 22 of thevessel 16 and descend to the bottom portion of thevessel 16. Thus, the insulatingoil 26 recirculates through the closedoil passage loop 43 composed of thevessel 16, the invertedU-shaped conduit 38, theoil filter 36, theconduit 42 and again thevessel 16. When the insulatingoil 26 has been cleaned, the pump is deenergized. - If an oil leak occurs at the
oil filter 36 which is lower than the bottom of thetap changer vessel 16, the insulatingoil 26 within thetap changer vessel 16 flows out from theinlet 40 of theconduit 38 through theconduit 38 and from the leak in theoil filter 36. As the oil leak continues, the insulatingoil 26 empties first from theconservator 28, and then the level of the insulatingoil 26 within theupper portion 22 of thetap changer vessel 16 gradually descends. This gradual descending of the oil level causes thefloat 54 to also gradually descend due to gravity and when the oil level in theupper portion 22 of thetap changer vessel 16 reaches thehole 44 in theconduit 36, thefloat 54 cannot provide any force to press thevalve 48 against thehole 44, thereby opening the air breazinghole 44 in thefirst conduit 38. Then, the air introduced within thevessel 16 from thebreazer 30 flows into thesmall hole 44 to prevent the further lowering of the oil level in thetap changer vessel 16 because the insulatingoil 26 in theupper portion 22 and thelower portion 24 of thevessel 16 is trapped in thevessel 16. Theoil 26 within the section of theconduit 38 to the left of thesmall hole 44 and the oil in theoil filter 36 flows out through the leak in thefilter 36. Therefore, even when an oil leak occurs in theoil filter 36, the insulatingoil 26 around thearc interrupting unit 20 in the vessel is maintained. - As has been described, according to the present invention, the oil conduit has formed therein an air breazing hole at a position higher than the interrupting unit, and the hole can be opened by a float valve only when the insulating oil in the vessel is reduced to lower than the level of the hole in the conduit. Therefore, the insulating oil cannot be emptied from the tap changer vessel, thus preventing accidents such as short-circuiting among taps.
- Fig. 2 illustrates another embodiment of the present invention, in which a closed
oil passage loop 56 of this embodiment is different from the embodiment shown in Fig. 1 in that an inverted-U shapedfirst conduit 58 shown in Fig. 2 extends outside of thetap changer vessel 16 without passing through theupper portion 22 of thevessel 16. This design is often employed where space for the first conduit is not available within thetap changer vessel 16. Thefirst conduit 58 has aninlet 60 in the bottom portion of the wall of thevessel 16 and extends through the top plate 19 of thetap changer 10. Thefirst conduit 58 is communicated at a position higher than the interrupting unit of the tap changer through aflow resistance pipe 62 with asecond conduit 64 having an outlet 65 connecting theoil filter 36 to theupper portion 22 of thevessel 16. Thepipe 62 is designed to exhibit a very high flow resistance against the insulatingoil 26 flowing therethrough as compared to the flow resistance in the section of theconduit 58 between theinlet 60 and thepipe 62. In the illustrated embodiment, thepipe 62 has a very small inner diameter compared to the inside diameter of theconduit 58. - In this embodiment, since the inner diameter of the
pip 62 is sufficiently small compared to the inside diameter of thefirst conduit 58, the flow resistance of thesmall pipe 62 is very high compared to the flow resistance of the flow path in theconduit 58 through theinlet 60. Therefore, most of the insulatingoil 26 supplied into theoil filter 36 is supplied from theinlet 60 at the bottom of thetap changer vessel 16 rather than from theupper portion 22 of thevessel 16 through thepipe 62 connected to the outlet end of thesecond conduit 64. Theoil 26 supplied through theconduit 58 to theoil filter 36 passes through the filter (not shown) of theoil filter 36 to be cleaned. The filteredoil 26 is returned through thesecond conduit 64 to theupper portion 22 of thevessel 16 and descends to the bottom portion of thevessel 16. Thus, the insulatingoil 26 recirculates through a closedoil passage loop 56 composed of thevessel 16, thefirst conduit 58, theoil filter 36, and thesecond conduit 64. When the insulatingoil 26 has been cleaned, the pump is deenergized. - If an oil leak occurs in the
oil filter 36 and the oil level in theupper portion 22 of thetap changer vessel 16 reaches the outlet 65 of thesecond conduit 64 which opens in the side wall of theupper portion 22 of thevessel 16, air introduced within thevessel 16 from thebreazer 30 flows into the interior of thefirst conduit 58 through the outlet 65 of thesecond conduit 64 and through the small-diameter pipe 62, preventing further lowering of the oil level in thetap changer vessel 16 because the insulatingoil 26 in theupper portion 22 and thelower portion 24 of thevessel 16 is trapped in thevessel 16. Theoil 26 within the section of theconduit 38 to the left of the small-diameter pipe 62 and theoil filter 36 flows out through the leak in thefilter 36. Therefore, even when an oil leak occurs in theoil filter 36, the insulatingoil 26 around thearc interrupting unit 20 in the vessel is maintained. - While the present invention has been described in terms of a tap changer of a particular type, the invention may be equally applicable to on-load tap changer of other types such as a tap selector switch which has the functions of both a tap selector and a diverter switch.
Claims (8)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8515/84U | 1984-01-24 | ||
JP851584U JPS60119723U (en) | 1984-01-24 | 1984-01-24 | Tap switching device under load |
JP10514/84U | 1984-01-25 | ||
JP1051484U JPS60121616U (en) | 1984-01-25 | 1984-01-25 | Tap switching device under load |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0150132A2 true EP0150132A2 (en) | 1985-07-31 |
EP0150132A3 EP0150132A3 (en) | 1986-01-22 |
EP0150132B1 EP0150132B1 (en) | 1988-08-17 |
Family
ID=26343044
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19850300443 Expired EP0150132B1 (en) | 1984-01-24 | 1985-01-23 | On-load tap changer |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0150132B1 (en) |
DE (1) | DE3564509D1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0191398A1 (en) * | 1985-02-13 | 1986-08-20 | Maschinenfabrik Reinhausen Gmbh | Oil-filled tap changer assembly with oil expansion vessel |
CN102737816A (en) * | 2012-06-25 | 2012-10-17 | 景宁畲族自治县电力公司 | Oil circuit system of transformer |
WO2014108246A1 (en) * | 2013-01-11 | 2014-07-17 | Maschinenfabrik Reinhausen Gmbh | On-load tap changer comprising a connection to the oil volume of a transformer |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102856044A (en) * | 2012-08-13 | 2013-01-02 | 吴江市东泰电力特种开关有限公司 | Online oil filtering device of on-load tap-changer |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3240724A1 (en) * | 1981-11-05 | 1983-05-11 | Mitsubishi Denki K.K., Tokyo | TRANSFORMER ARRANGEMENT |
EP0114648A2 (en) * | 1983-01-22 | 1984-08-01 | Hitachi, Ltd. | Onload tap-changing transformer |
-
1985
- 1985-01-23 EP EP19850300443 patent/EP0150132B1/en not_active Expired
- 1985-01-23 DE DE8585300443T patent/DE3564509D1/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3240724A1 (en) * | 1981-11-05 | 1983-05-11 | Mitsubishi Denki K.K., Tokyo | TRANSFORMER ARRANGEMENT |
EP0114648A2 (en) * | 1983-01-22 | 1984-08-01 | Hitachi, Ltd. | Onload tap-changing transformer |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0191398A1 (en) * | 1985-02-13 | 1986-08-20 | Maschinenfabrik Reinhausen Gmbh | Oil-filled tap changer assembly with oil expansion vessel |
CN102737816A (en) * | 2012-06-25 | 2012-10-17 | 景宁畲族自治县电力公司 | Oil circuit system of transformer |
WO2014108246A1 (en) * | 2013-01-11 | 2014-07-17 | Maschinenfabrik Reinhausen Gmbh | On-load tap changer comprising a connection to the oil volume of a transformer |
Also Published As
Publication number | Publication date |
---|---|
EP0150132A3 (en) | 1986-01-22 |
EP0150132B1 (en) | 1988-08-17 |
DE3564509D1 (en) | 1988-09-22 |
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