On-load tap changer

Abstract

The present invention provides a plurality of winding taps N1, ..., N J ,…,N N The present invention relates to an on-load tap changer 1 for switching between power lines without interrupting power interruptions. The on-load tap changer 1 comprises a selector 3 and an on-load changeover switch 4. The on-load changeover switch 4 comprises a first load branch 5.1 and a second load branch 5.2. Each of the load branches 5.1, 5.2 comprises at least one vacuum valve 6.1, 6.2, 7.1, 7.2. Each of the vacuum valves 6.1, 6.2, 7.1, 7.2 can be switched between an open state 31 in which the movable contact 11 and the fixed contact 12 do not contact each other, and a closed state in which the movable contact 11 and the fixed contact 12 contact each other at at least one contact point 13. Each of the vacuum valves 6.1, 6.2, 7.1, 7.2 has a defined spherical area 14 starting from the contact point 13. The on-load changeover switch 4 is configured so that the current-carrying parts of the on-load changeover switch 4 are arranged outside the defined area 14 and so that the vacuum valves 6.1, 6.2, 7.1, 7.2 are arranged in the housing 29.

Description

[Technical field]

[0001] The present invention relates to an on-load tap changer for non-interruptive switching between multiple winding taps of a tapped transformer. [Background technology]

[0002] Generally, known on-load tap changers consist of one selector for selecting in the no-current state the respective winding tap of the transformer to the winding tap to which it has to be changed, and one on-load changeover switch (4) for actually switching on-load from the previous winding tap to the new winding tap selected. The changeover is carried out by mechanically operating different switches. With increasing loads, i.e. with further increases in currents and voltages, the demands on the operating mechanism also increase. Summary of the Invention [Problem to be solved by the invention]

[0003] It is therefore an object of the present invention to provide an improved on-load tap changer which can withstand increased mechanical and electrical loads even at higher energization and voltage applications. [Means for solving the problem]

[0004] This problem is solved by an on-load tap changer according to the independent claim 1. Further embodiments are defined in the dependent claims.

[0005] According to the improved technical idea, an on-load tap changer is proposed for switching between a number of winding taps of a tap transformer without interruption. The on-load tap changer comprises a selector for preselecting in a no-current state the winding tap to be switched and an on-load changeover switch for actually switching on-load from the preceding winding tap to the preselected winding tap. The on-load changeover switch comprises a first load branch and a second load branch, and at least one vacuum valve in the first load branch and in the second load branch. Each vacuum valve comprises a moving contact and a fixed contact, and can take an open state in which the moving contact and the fixed contact do not contact each other, and a closed state in which the moving contact and the fixed contact contact each other at at least one contact point. Each vacuum valve has a spherical area determined by the contact point. The vacuum valves of the on-load changeover switch are arranged in the housing such that the current carrying parts of the on-load changeover switch are outside the defined area. According to at least one preferred embodiment, the on-load tap changer is configured such that upon operation of the vacuum valves from the closed state to the open state, the currently current carrying parts of the on-load changeover switch are located outside the defined area.

[0006] This arrangement allows for a compact construction of the on-load tap changer whilst maintaining more reliable function despite increased currents and voltages.

[0007] According to at least one embodiment, the spherical area centered on the contact point has a radius of at least 80 mm and at most 200 mm.

[0008] According to at least one embodiment, the current carrying parts of the on-load changeover switch are a first current carrying member of the first load branch and / or a second current carrying member of the second load branch and / or a third current carrying member of the first load branch and / or a fourth current carrying member of the second load branch and / or a current carrying element and / or a first mechanical switching contact and / or a second mechanical switching contact, a bridge resistor and / or the vacuum valve in the closed state, the parts being arranged outside the spherical area of ​​each vacuum valve.

[0009] According to at least one embodiment, the first load branch of the on-load changeover switch includes a first vacuum valve and a second vacuum valve.

[0010] According to at least one embodiment, at least the first current-carrying member, the second current-carrying member, the second vacuum valve of the first load branch, the third current-carrying member and the first mechanical opening and closing contact are positioned outside the defined area of ​​the first vacuum valve of the first load branch.

[0011] According to at least one embodiment, the second load branch of the on-load changeover switch includes a first vacuum valve and a second vacuum valve.

[0012] According to at least one embodiment, at least the first current-carrying member, the second current-carrying member, the second vacuum valve of the second load branch, the fourth current-carrying member and the second mechanical opening and closing contact are positioned outside the defined area of ​​the first vacuum valve of the second load branch.

[0013] According to at least one embodiment, at least the second vacuum valve, the third current-carrying member, the fourth current-carrying member and the mechanical opening and closing element of the second load branch are positioned outside the defined area of ​​the second vacuum valve of the first load branch.

[0014] According to at least one embodiment, at least the second vacuum valve, the third current carrying member, the fourth current carrying member and the mechanical opening and closing element of the first load branch are positioned outside the defined area of ​​the second vacuum valve of the second load branch.

[0015] According to at least one embodiment, a first winding tap is electrically connected to the ground conductive member via a series circuit consisting of a first vacuum valve and a second vacuum valve across the first load branch, and a second winding tap is electrically connected to the ground conductive member via a series circuit consisting of a first vacuum valve and a second vacuum valve across the second load branch.

[0016] According to at least one embodiment, one bridge resistor each is arranged in parallel with the first vacuum valve of the first and second load branches.

[0017] According to at least one embodiment, the bridge resistor is located outside the defined area of ​​the second vacuum valve of the first load branch and outside the defined area of ​​the second vacuum valve of the second load branch.

[0018] According to at least one embodiment, the first mechanical switching contact is disposed between a second vacuum valve of the first load branch and the ground conductive member, and the second mechanical switching contact is disposed between a second vacuum valve of the second load branch and the ground conductive member.

[0019] According to at least one embodiment, the mechanical switching contacts are arranged outside the defined area of ​​the vacuum valve.

[0020] According to at least one embodiment, these mechanical switching contacts are configured as circuit breakers.

[0021] According to at least one embodiment, within the first load branch, the first vacuum valve and the second vacuum valve are electrically connected to each other via a first current-carrying member, and the second vacuum valve and the first mechanical opening and closing element are electrically connected to each other via a third current-carrying member, and within the second load branch, the first vacuum valve and the second vacuum valve are electrically connected to each other via a second current-carrying member, and the second vacuum valve and the first mechanical opening and closing contact element are electrically connected to each other via a fourth current-carrying member.

[0022] According to at least one embodiment, each of these current carrying members is electrically connected to the vacuum valve via a current carrying element.

[0023] According to at least one embodiment, each of the current-carrying members has a first end and a second end, where the first end is electrically connected to a movable contact of the vacuum valve via the current-carrying element, and the second end is electrically connected to a fixed contact of the vacuum valve via the current-carrying element.

[0024] According to at least one embodiment, a respective fixed main contact is further provided in parallel with each load branch, which takes over at least a portion of the sustained current during steady-state operation and is directly conductively connected to the earth conductive member.

[0025] According to at least one embodiment, a plurality of vacuum valves are arranged in a circular fashion around the switching shaft.

[0026] According to at least one embodiment, the first mechanical switching contact and the second mechanical switching contact are arranged as mirror images with respect to an axis, which in this case lies on the switching axis.

[0027] According to at least one embodiment, two vacuum valves respectively are arranged as mirror images relative to the axis.

[0028] The present invention will be described in detail below with reference to the drawings based on representative embodiments. Components that are functionally the same or exhibit the same effect may be labeled with the same reference numerals. The same components or components having the same function are described only with respect to the figure in which they first appear in some cases. The description does not necessarily have to be repeated in the subsequent figures. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic diagram of a tap transformer having an on-load tap changer according to an improved concept. [Diagram 2] FIG. 2 is a schematic diagram of a winding tap of a tap transformer. [Diagram 3] 1 is a schematic diagram of an exemplary embodiment of an on-load tap changer according to an improved concept; [Figure 4a] A typical switching sequence of an on-load tap changer according to FIG. [Figure 4b] A typical switching sequence of an on-load tap changer according to FIG. [Figure 4c] A typical switching sequence of an on-load tap changer according to FIG. [Figure 4d] A typical switching sequence of an on-load tap changer according to FIG. [Figure 4e] A typical switching sequence of an on-load tap changer according to FIG. [Figure 4f] A typical switching sequence of an on-load tap changer according to FIG. [Diagram 5] 1 shows a representative embodiment of an on-load changeover switch according to an improved technical concept. [Figure 6] 6 shows the exemplary embodiment according to FIG. 5 from another angle. [Figure 7] 6 shows the exemplary embodiment according to FIG. 5 from another angle. [Figure 8] 6 shows the exemplary embodiment according to FIG. 5 from another angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] These figures show only embodiments of the present invention and are not intended to be limiting to the illustrated embodiments.

[0031] 1 is a schematic diagram of a tap transformer 2 comprising an on-load tap changer 1 having a selector 3 and an on-load changeover switch 4. The on-load tap changer 1 is driven by an electric motor 22.

[0032] FIG. 2 shows a number of different winding taps N1,…,N J ,…,N N 1 shows a schematic diagram of the regulating winding 25 of the tapped transformer 2 (see FIG. 1) having winding taps N1, ..., N J ,…,N N is connected or disconnected by an on-load tap changer 1. The disconnection or connection can be performed by any means, such as a selector 3, an on-load changer switch 4, etc. The on-load tap changer 1 is operated by an electric motor 22.

[0033] 3 is a schematic diagram of an exemplary embodiment of an on-load tap changer 1. According to an improved concept, the on-load tap changer 1 is configured to include winding taps N1, ..., N2 of a tap transformer 2. J ,…,N N The total number of these fixed contacts is equal to the winding taps N1, ..., N of the tap transformer 2. J ,…,N NThe number of the fixed contacts 23.1, 23.2 of the regulating winding 25 depends on the number of the fixed contacts 23.1, 23.2 of the regulating winding 25. The on-load tap changer 1 further comprises a first selector movable contact 24.1 and a second selector movable contact 24.2, which can contact the respective fixed contacts 23.1, 23.2 of the regulating winding 25, respectively. The on-load tap changer 1 further comprises an on-load changeover switch 4 having a first load branch 5.1 and a second load branch 5.2. According to this representative embodiment, the first load branch 5.1 connects the first fixed contact 23.1 to the earth conductive member 8 through a series circuit consisting of the first vacuum valve 6.1 and the second vacuum valve 6.2, and the second load branch 5.2 connects the second fixed contact 23.2 to the earth conductive member 8 through a series circuit consisting of the first vacuum valve 7.1 and the second vacuum valve 7.2. A bridge resistor 9.1 or 9.2 is connected in parallel to the respective first vacuum valve 6.1 or 7.1. A first mechanical switching element 18.1 is arranged between the second vacuum valve 6.2 and the earth conductive member 8, and a second mechanical switching element 18.2 is arranged between the second vacuum valve 7.2 and the earth conductive member 8. A first current-carrying member 10.1 conductively connects the first vacuum valve 6.1 and the second vacuum valve 6.2 to each other, and a second current-carrying member 10.2 conductively connects the first vacuum valve 7.1 and the second vacuum valve 7.2 to each other. Furthermore, a third current-carrying member 10.3 connects the second vacuum valve 6.2 to the first mechanical switching element 18.1, and a fourth current-carrying member 10.4 connects the second vacuum valve 7.2 to the second mechanical switching element 18.2. Furthermore, additional fixed main contacts 19.1, 19.2 are arranged in parallel with the respective load branches 5.1, 5.2. Figure 2 shows the on-load tap changer 1 in steady state. In the steady state, at least a part of the load current passes through the fixed main contact 19.1, and is then conducted from the winding tap through the first fixed contact 23.1 to the ground conductive member 8. In particular, at least a part of the load current is greater than the amount of load current passing through the load branch 5.1.

[0034] 4a-4e show a typical switching sequence of the on-load tap changer 1 according to the improved concept, in which the second fixed contact 23.2 is switched to the first fixed contact 23.1 or to the corresponding winding taps N1, ..., N2 of the tap transformer 2. J ,…,NN can be switched to.

[0035] In step a (see FIG. 4a), the fixed main contact 10.2 is closed or remains closed. The on-load tap changer 1 is in a steady state, in which at least a portion of the load current is routed through the fixed main contact 19.2 to the corresponding winding tap N. J+1 2 and then through the second fixed contact 23.2 to the ground conductive member 8. In particular, at least a portion of the load current is greater than the amount of load current passing through the load branch 5.2.

[0036] In step b (see FIG. 4b), the fixed main contact 19.2 is opened and the first mechanical switching contact 18.1 is closed, and the current flows to the ground conductive member 8 via the first vacuum valve 7.1 and the second current-carrying member 10.2 of the second load branch 5.2, the second vacuum valve 7.2 and the fourth current-carrying member 10.4 of the second load branch 5.2, and the second mechanical switching contact 18.2.

[0037] In step c (see FIG. 4c), the first vacuum valve 7.1 of the second load branch 5.2 is opened. During the opening process, the second vacuum valve 7.2, the fourth current-carrying member 10.4 and the second mechanical switching contact 18.2 are electrically conducting and are located spatially outside the defined area 14 (see, for example, FIGS. 6-8) of the vacuum valve 7.1. The current then passes from the fixed contact 23.2 to the ground conductive member 8 via the bridge resistor 9.2, the second vacuum valve 7.2, the fourth current-carrying member 10.4 and the second mechanical switching contact 18.2.

[0038] In step d (FIG. 4d), the second vacuum valve 6.2 of the first load branch 5.1 is closed. The load current is now branched into the first load branch 5.1 and into the second load branch 5.2. Furthermore, a circulating current is superimposed.

[0039] In step e (see FIG. 4e), the second vacuum valve 7.2 of the second load branch 5.2 is opened. During the opening process, the second vacuum valve 6.2 of the first load branch 5.1, the first mechanical switching element 18.1 of the first load branch 5.1, the second mechanical switching element 18.2 of the second load branch 5.2 and the connection current-carrying member 27 to the bridge resistor 9.1 or 9.2 of the first load branch 5.1 or the second load branch 5.2 are electrically conducting and are located spatially outside the defined area 14 (see, for example, FIG. 6-8) of the vacuum valve 7.2 of the second load branch 5.2. The current then passes from the fixed contact 23.2 to the ground conductive member 8 via the bridge resistor 9.1, the second vacuum valve 6.2 of the first load branch 5.1, the third current-carrying member 10.3 and the first mechanical switching contact 18.1.

[0040] In step f (see FIG. 4f), the first vacuum valve 6.1 of the first load branch 5.1 is closed. The current then passes through the first vacuum valve 6.1, the first current-carrying member 10.1, the second vacuum valve 6.2, the third current-carrying member 10.3 and the first mechanical switching contact 18.1 to the ground conductive member 8.

[0041] In step g (see FIG. 3), the fixed main contact 19.1 in the first load branch 5.1 is closed and the second mechanical switching contact 18.2 in the second load branch 5.2 is opened. The on-load tap changer 1 is again in steady state, as shown and described in FIG.

[0042] 5 and 6 each show a representative embodiment of the on-load changeover switch 4 according to the improved technical idea. In this case, for the sake of clarity, the on-load changeover switch 4 is projected from two different perspectives. Four vacuum valves 6.1, 6.2, 7.1, 7.2 are arranged in a circular shape around a changeover axis 20 and each have one moving contact 11 and one fixed contact 12. The vacuum valves 6.1 and 6.2 are conductively connected to each other via a first current-carrying member 10.1, and the vacuum valves 7.1 and 7.2 are conductively connected to each other via a second current-carrying member 10.2. The conductive connection is realized by a current-carrying element 17, which is formed, for example, as a bolt and / or a twisted wire. In this case, a first end of the first current-carrying member 10.1 is electrically connected to the moving contact 11 of the vacuum valve 6.1 via the current-carrying element 17, and a second end of it is electrically connected to the fixed contact 12 of the vacuum valve 6.2 via the current-carrying element 17. A first end of the second current-carrying member 10.2 is electrically connected to the movable contact 11 of the vacuum valve 7.1 via a current-carrying element 17, and a second end of the second current-carrying member 10.2 is electrically connected to the fixed contact 12 of the vacuum valve 7.2 via a current-carrying element 17. The movable contact 11 and the fixed contact 12 of each vacuum valve 6.1, 6.2, 7.1, 7.2 are in contact at least one point 13 in the closed state of these vacuum valves. Each vacuum valve 6.1, 6.2, 7.1, 7.2 defines a respective spherical area 14 by (starting at) the respective contact point 13. For the sake of clarity, the contacts 11 and 12 and the contact points 13 of these contact points are depicted and numbered in Figs. 4 and 5 only for a few vacuum valves.

[0043] 7 and 8 are plan views of a representative embodiment of the on-load changeover switch, respectively. The on-load changeover switch 4 has a housing 29 in which the vacuum valves 6.1, 6.2, 7.1 and 7.2 are arranged. The housing 29 is substantially cylindrical and made of glass-fiber reinforced plastic. The vacuum valves 6.1 and 6.2 are arranged in the housing 29 in a mirror image manner with respect to the vacuum valves 7.1 and 7.2. For example, the vacuum valve 7.2 is arranged opposite the vacuum valve 6.1, and the vacuum valve 7.1 is arranged opposite the vacuum valve 6.2. This creates a maximum distance between the vacuum valves 6.1 and 7.1, and between the vacuum valves 6.2 and 7.2. Between the vacuum valves 6.1 and 6.2 of the first load branch 5.1 and between the vacuum valves 7.1 and 7.2 of the second load branch 5.2, a first mechanical switching contact 18.1 and a second mechanical switching contact 18.2 are arranged, respectively, likewise mirror images of each other. Fig. 7 shows that the second current-carrying member 10.2 and the second vacuum valve 7.2 of the second load branch 5.2 are arranged outside the defined area 14 of the first vacuum valve 7.1 of the second load branch 5.2. Fig. 8 further shows that the second vacuum valve 6.2 of the first load branch 5.1 is arranged outside the defined area 14 of the second vacuum valve 7.2 of the second load branch 5.2. The present application relates to the invention described in the claims, but may also include the following configurations as other aspects. 1. Multiple winding taps (N 1 ,…,N J ,…,N N ) without interrupting a power outage, the on-load tap changer (1) comprising: -Selected winding tap (N J ) in a currentless state; - Leading winding tap (N J-1 ) preselected winding taps (N J ) for actually switching on and off when on load; at least one vacuum valve (6.1, 6.2) in the first load branch (5.1) and at least one vacuum valve (7.1, 7.2) in the second load branch (5.2); having The on-load changeover switch (4) has the first load branch portion (5.1) and the second load branch portion (5.2), - each vacuum valve (6.1, 6.2, 7.1, 7.2) has one moving contact (11) and one fixed contact (12), - each vacuum valve (6.1, 6.2, 7.1, 7.2) has an open state (31) in which the movable contact (11) and the fixed contact (12) are not in contact with each other, and a closed state in which the movable contact (11) and the fixed contact (12) are in contact with each other at at least one contact point (13), a spherical area (14) is defined by the contact point (13) between the fixed contact (12) and the movable contact (11) of each vacuum valve (6.1, 6.2, 7.1, 7.2), - an on-load tap changer in which the vacuum valves (6.1, 6.2, 7.1, 7.2) of the on-load tap changer (4) are arranged such that the live parts of the on-load tap changer (4) are arranged outside the defined area (14). 2. 2. An on-load tap changer according to claim 1, wherein the spherical area (14) centred on the contact point (13) has a radius of at least 80 mm and at most 200 mm. 3. 1. An on-load tap changer according to claim 1, wherein the current carrying parts of the on-load changeover switch (4) are the first current carrying member (10.1) of the first load branch (5.1) or the second current carrying member (10.2) of the second load branch (5.2) or a current carrying element (17) or a first mechanical switching contact (18.1) or a second mechanical switching contact (18.2), which are arranged outside the spherical area (14) of each vacuum valve (6.1, 6.2, 7.1, 7.2). 4. the second load branch (5.2) of the on-load changeover switch (4) comprises a first vacuum valve (7.1) and a second vacuum valve (7.2); An on-load tap changer according to any one of claims 1 to 3, wherein at least the second current carrying member (10.2), the second vacuum valve (7.2) of the second load branch (5.2) and a fourth current carrying member (10,4) are arranged outside the defined area (14) of the first vacuum valve (7.1) of the second load branch (5.2). 5. the first load branch (5.1) of the on-load changeover switch (4) comprises a first vacuum valve (6.1) and a second vacuum valve (6.2); - An on-load tap changer according to any one of claims 1 to 3, wherein at least the second vacuum valve (6.2), the third current-carrying member (10.3) and the fourth current-carrying member (10.4) of the first load branch (5.1) are arranged outside the defined area (14) of the second vacuum valve (7.2) of the second load branch (5.2). 6. The first load branch (5.1) is connected to one winding tap (N J ) is electrically connected to the ground conductive member (8); The second load branch (5.2) is connected to one winding tap (N J+1 6. An on-load tap changer as claimed in claim 4 or 5, wherein the on-load tap changer is electrically connected to the earth conductive member (8). 7. - the first mechanical switching contact (18.1) is arranged between the second vacuum valve (6.2) of the first load branch (5.1) and a ground conductive member (8), The on-load tap changer according to claim 3, wherein the second mechanical switching contact (18.2) is arranged between the second vacuum valve (7.2) of the second load branch (5.2) and the earth conductive member (8). 8. 8. An on-load tap changer according to claim 7, wherein the mechanical switching contacts (18.1, 18.2) are configured as disconnectors. 9. in the first load branch (5.1), the first vacuum valve (6.1) and the second vacuum valve (6.2) are electrically connected to each other via a first current-carrying member (10.1), and the second vacuum valve (6.2) and the first mechanical switching contact (18.1) are electrically connected to each other via a third current-carrying member (10.3), - An on-load tap changer according to any one of claims 1 to 8, wherein within the second load branch section (5.2), the first vacuum valve (7.1) and the second vacuum valve (7.2) are electrically connected to each other via a second current-carrying member (10.2), and the second vacuum valve (7.2) and the first mechanical opening and closing contact (18.2) are conductively connected to each other via a fourth current-carrying member (10.4). 10. - an on-load tap changer as described in claim 9, wherein each of said plurality of current-carrying members (10.1, 10.2, 10.3, 10.4) is electrically connected to said vacuum valve (6.1, 6.2, 7.1, 7.2) via a current-carrying element (17). 11. - An on-load tap changer according to any one of claims 1 to 10, further comprising a fixed main contact (19.1, 19.2) in parallel with each of the load branches (5.1, 5.2), the fixed main contact (19.1, 19.2) being electrically connected directly to the earthing conductive member (8) and taking over at least a part of the sustained current during steady-state operation. 12. The on-load tap changer according to any one of 1 to 11 above, wherein the vacuum valves (6.1, 6.2, 7.1, 7.2) are arranged in a circular shape around a switching shaft (20). 13. - An on-load tap changer according to any one of claims 1 to 12, wherein the first mechanical switching contact (18.1) and the second mechanical switching contact (18.2) are arranged in a mirror image manner with respect to the axis (21) of the switching shaft (20). [Explanation of symbols]

[0044] 1 On-load tap changer 2 tap transformer 3. Selector 4 On-load switching switch 5.1 First load branch 5.2 Second load branch 6.1 First vacuum valve of the first load branch 6.2 Second vacuum valve of the first load branch 7.1 First vacuum valve of second load branch 7.2 Second vacuum valve of second load branch 8. Grounding Conductive Members 9.1,9.2 Bridge resistance 10.1 First current-carrying member 10.2 Second current-carrying member 11 Movable contact 12 Fixed contact 13 Center point / contact point 14 Determined Areas, Spherical Areas 15.1,15.2 First end 16.1,16.2 Second end 17 Current carrying elements 18.1 First mechanical switching contact 18.2 Second mechanical switching contact 19.1,19.2 Fixed main contact 20 Switching axis 21 axis 22 Electric motor 23.1, 23.2 Selector fixed contacts 24.1, 24.2 Selector movable contact 25 Adjustment Winding 27 Connecting current-carrying parts 29 Housing (N1,…,N J ,…,N N ) Winding tap

Claims

1. A plurality of winding taps (N １ , …, N Ｊ , …, N Ｎ 2. An on-load tap changer (1) for switching between two loads without interruption, the on-load tap changer (1) comprising: - Selected winding tap (N Ｊ ) in a currentless state; - the preceding winding tap (N Ｊ－１ ) preselected winding taps (N Ｊ ) for actually switching on and off when on load; at least one vacuum valve (6.1, 6.2) in the first load branch (5.1) and at least one vacuum valve (7.1, 7.2) in the second load branch (5.2); having The on-load changeover switch (4) has the first load branch (5.1) and the second load branch (5.2), each vacuum valve (6.1, 6.2, 7.1, 7.2) has one moving contact (11) and one fixed contact (12); - in said on-load tap changer, each vacuum valve (6.1, 6.2, 7.1, 7.2) has an open state (31) in which the movable contact (11) and the fixed contact (12) are not in contact with each other, and a closed state in which the movable contact (11) and the fixed contact (12) are in contact with each other at at least one contact point (13), a spherical area (14) is defined by the contact points (13) of the fixed contact (12) and the movable contact (11) of each vacuum valve (6.1, 6.2, 7.1, 7.2), - the vacuum valves (6.1, 6.2, 7.1, 7.2) of the on-load changeover switch (4) are arranged so that the live parts of the on-load changeover switch (4) are arranged outside the defined area (14), - an on-load tap changer, characterized in that the current-carrying parts of the on-load changeover switch (4) are a first current-carrying member (10.1) of the first load branch (5.1) or a second current-carrying member (10.2) of the second load branch (5.2) or a current-carrying element (17) or a first mechanical switching contact (18.1) or a second mechanical switching contact (18.2), which are arranged outside the spherical area (14) of each vacuum valve (6.1, 6.2, 7.1, 7.2).

2. An on-load tap changer according to claim 1, wherein the spherical area (14) centred on the contact point (13) has a radius of at least 80 mm and at most 200 mm.

3. the second load branch (5.2) of the on-load changeover switch (4) comprises a first vacuum valve (7.1) and a second vacuum valve (7.2); 3. An on-load tap changer according to claim 1 or 2, wherein at least the second current carrying member (10.2), the second vacuum valve (7.2) of the second load branch (5.2) and the fourth current carrying member (10,4) are arranged outside the defined area (14) of the first vacuum valve (7.1) of the second load branch (5.2).

4. the first load branch (5.1) of the on-load changeover switch (4) comprises a first vacuum valve (6.1) and a second vacuum valve (6.2); 3. An on-load tap changer according to claim 1 or 2, wherein at least the second vacuum valve (6.2), the third current-carrying member (10.3) and the fourth current-carrying member (10.4) of the first load branch (5.1) are arranged outside the defined area (14) of the second vacuum valve (7.2) of the second load branch (5.2).

5. - the first load branch (5.1) is connected to one winding tap (N) via a series circuit consisting of the first vacuum valve (6.1) and the second vacuum valve (6.2) of the first load branch (5.1); Ｊ ) is electrically connected to the ground conductive member (8); - the second load branch (5.2) is connected to one winding tap (N Ｊ＋１ 5. An on-load tap changer as claimed in claim 3 or 4, characterized in that the first terminal is electrically connected to the earth conductive member (8).

6. - said first mechanical switching contact (18.1) is arranged between said second vacuum valve (6.2) of said first load branch (5.1) and a ground conductive member (8); - on-load tap changer according to claim 1 or 2, characterized in that the second mechanical switching contact (18.2) is arranged between the second vacuum valve (7.2) of the second load branch (5.2) and a ground conductive member (8).

7. - on-load tap changer according to claim 6, characterized in that the mechanical switching contacts (18.1, 18.2) are designed as disconnectors.

8. in said first load branch (5.1), a first vacuum valve (6.1) and a second vacuum valve (6.2) are electrically connected to each other via a first current-carrying member (10.1) and said second vacuum valve (6.2) and a first mechanical switching contact (18.1) are electrically connected to each other via a third current-carrying member (10.3); - in the second load branch (5.2), the first vacuum valve (7.1) and the second vacuum valve (7.2) are electrically connected to each other via a second current-carrying member (10.2), and the second vacuum valve (7.2) and the first mechanical switching contact (18.2) are conductively connected to each other via a fourth current-carrying member (10.4).

9. 9. An on-load tap changer according to claim 8, wherein each of said plurality of current-carrying members (10.1, 10.2, 10.3, 10.4) is electrically connected to said vacuum valve (6.1, 6.2, 7.1, 7.2) via a current-carrying element (17).

10. 10. An on-load tap changer according to claim 1, further comprising a fixed main contact (19.1, 19.2) in each case which is provided in parallel with each load branch (5.1, 5.2) and which takes over at least a portion of the continuous current during steady-state operation and is directly electrically connected to the earth conductive member (8).

11. - on-load tap changer according to any one of the preceding claims, characterized in that the vacuum valves (6.1, 6.2, 7.1, 7.2) are arranged in a circular fashion around a switching axis (20).

12. - on-load tap changer according to any one of claims 1 to 11, characterized in that the first mechanical switching contact (18.1) and the second mechanical switching contact (18.2) are arranged in a mirror image manner relative to the axis (21) of the switching shaft (20).

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