Coupling structure for combined on-load tap-changer

Abstract

The utility model discloses a connecting structure for a combined on-load tap-changer, which comprises a cylinder type potential resistor body, and the cylinder type potential resistor body comprises a cylinder type potential resistor and a tap selector bottom support. The connection structure further comprises a connection leading-out terminal, a wire fixing device, a connection wire and a tapping selector connection support, the tapping selector connection support is installed on the cylinder type potential resistor, and the connection leading-out terminal and the wire fixing device are installed on the tapping selector bottom support. The connecting leading-out terminal, the wire fixing device and the tapping selector connecting support are connected through connecting wires, and the connecting wires are in an insulated horizontal state through the wire fixing device. According to the connecting structure, an existing structure is improved, connecting and fixing are convenient, the connecting wire can be in an insulation horizontal state so as to meet actual use requirements, and the connecting structure is simple in overall structure, convenient to operate and suitable for application and popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of on-load tap-changers in transformers, and particularly relates to a connection structure for a combined on-load tap-changer. Background Art

[0002] On-load tap-changers are divided into two major categories, namely composite type and combined type, according to the structural mode. Among them, the composite type combines the tap selector and the switching switch together, and there is only the on-load tap-changer body, while the combined type is composed of a tap selector and a switching switch. The tap selector and the switching switch of the combined on-load tap-changer are separately packed and shipped to the user, and the user assembles the tap selector and the switching switch of the combined on-load tap-changer to complete the mechanical connection and electrical connection between the tap selector and the switching switch.

[0003] The voltage regulating circuit is the circuit formed when the transformer winding regulates voltage. The on-load voltage regulating circuit is divided into a basic voltage regulating circuit, a three-phase voltage regulating circuit, an autotransformer voltage regulating circuit, and an industrial transformer voltage regulating circuit. The basic voltage regulating circuit is further divided into three types: linear voltage regulation, positive and negative voltage regulation, and coarse and fine voltage regulation. In addition, the windings of on-load voltage regulating transformers are usually composed of a basic winding and a tap voltage regulating winding. Linear voltage regulation: The basic winding and the tap voltage regulating winding are connected together, and the voltage regulation range depends on the number of turns of the tap voltage regulating winding. Positive and negative voltage regulation: The basic winding can be connected to the tap voltage regulating winding in a positive or negative manner, and the voltage regulation range is doubled. Coarse and fine voltage regulation: There is a section of coarse adjustment on the basic winding, which is used to connect the tap voltage regulating winding in a positive or negative manner, and the voltage regulation range is expanded by one time.

[0004] The on-load tap-changer with linear voltage regulation does not have a conversion selector, while the on-load tap-changers with positive and negative voltage regulation and coarse and fine voltage regulation have a conversion selector. The conversion selector of the on-load tap-changer with positive and negative voltage regulation is used to connect the tap voltage regulating winding to the basic winding in a positive or negative manner. The conversion selector of the on-load tap-changer with coarse and fine voltage regulation is used to connect the basic winding to the tap voltage regulating winding in a positive or negative manner. When the conversion selector moves from the positive connection position to the negative connection position, the tap voltage regulating winding is disconnected from the main winding, and the potential of the tap voltage regulating winding is floating at this time. The floating potential is usually different from the potential when the tap voltage regulating winding is connected to the main winding. When the conversion selector operates, a recovery voltage will be generated between the opened and closed contacts. When the recovery voltage is greater than the allowable value, a large amount of gas will be generated due to the discharge of the moving and static contacts in the conversion selector, and in severe cases, the moving and static contacts in the conversion selector will be burned out.

[0005] In order to reduce the recovery voltage generated when the conversion selector operates, there are many methods. Currently, the method of connecting a potential resistor is generally adopted both at home and abroad. The principle is to connect a solid resistor with a high resistance value in the middle of the tap voltage regulating winding, and the other end is connected to the lead-out terminal of the on-load tap-changer, so as to ensure that when the conversion selector operates, the tap voltage regulating winding is connected with a fixed potential.

[0006] There are two types of potential resistors matched with the combined on-load tap-changer, one is a cylindrical potential resistor and the other is a plate potential resistor. The cylindrical potential resistor installs the resistance element in a cylindrical insulating cylinder, usually at the bottom of the tap selector of the on-load tap-changer.

[0007] One end of the resistance element in the cylindrical potential resistor is connected to the connection bracket at the top of the cylindrical potential resistor, and this connection bracket is tightly assembled with the bottom bracket of the tap selector. Since the bottom bracket of the tap selector is equipotential with the lead-out terminal of the on-load tap-changer, this end does not need to be connected by a connecting wire. The other end of the resistance element is provided with a connection lead-out terminal, and the connection lead-out terminal is connected to the contact terminal of the tap selector using a connecting wire.

[0008] The connection lead-out terminal in the cylindrical potential resistor is a wiring rod, which is assembled on the circular insulating cylinder wall and fastened with a nut. After the wire is assembled on the wiring rod, it is fastened with another nut. The wire is between the two nuts. Since the connecting wire and the cylindrical potential resistor are not provided to the user after being connected, the two nuts on the wiring rod are overlapped and fastened before being provided to the user. When the user uses it, the outer nut is withdrawn and the wire is assembled. Often, the two nuts are withdrawn together, resulting in the loosening of the terminal post and the loosening and falling off of the resistance element at the other end of the terminal post.

[0009] As Figures 1 to 5 shown, the connecting wire in the existing cylindrical potential resistor is generally connected and assembled by the user himself. The two ends of the connecting wire are formed by winding copper bars. If the winding direction of the installed winding is opposite to the tightening direction of the nut, the copper bar winding will spread, which is not conducive to the connection of the wire. The connecting wire uses a copper bar with a smaller diameter, which can be bent and wound arbitrarily. Due to different user habits, the three connecting wires are formed differently, and it is possible that the insulation level of the wire to the ground cannot be guaranteed. After the insulation of the connecting wire breaks down, arc discharge occurs. Finally, to replace the connecting wire, the transformer cover needs to be lifted to handle it, and relevant experiments need to be carried out after completion, which requires huge relevant costs and compensation.

[0010] When the connection bracket at the top of the cylindrical potential resistor is tightly assembled with the bottom bracket of the tap selector, bolts and elastic pins are used for tightening. Since the bottom bracket of the tap selector is a cast aluminum part, occasionally aluminum chips will be generated after the screws and elastic pins are assembled. Metal foreign objects such as aluminum chips in the oil chamber of the transformer will seriously affect the safe operation of the transformer. At worst, the insulation breaks down, and at best, the transformer coil burns out. Therefore, the existing fixing method is improved to provide a connection structure that is convenient for operation and use to meet the actual use requirements of the combined on-load tap-changer. Summary of the Invention

[0011] The technical problem to be solved by the present utility model is to address the problems existing in the background art. In order to ensure the usage requirements of the combined on-load tap-changer, a connection structure for operation is provided. By using this connection structure, not only is the connection convenient, but it can also meet the safe operation of the transformer, thus meeting the actual usage requirements. Specifically, it is a connection structure for a combined on-load tap-changer.

[0012] To solve the above technical problems, the technical solution adopted by the present utility model is as follows: A connection structure for a combined on-load tap-changer, including a cylindrical potential resistor body. The cylindrical potential resistor body includes a cylindrical potential resistor and a bottom bracket of the tap selector. The connection structure further includes connection lead terminals, a wire fixing device, connection wires, and a tap selector connection support. Three tap selector connection supports are installed on the cylindrical potential resistor, and three connection lead terminals and a wire fixing device are installed on the bottom bracket of the tap selector. The connection lead terminals, the wire fixing device, and the tap selector connection support are connected by connection wires, and the connection wires are kept at an insulating level through the wire fixing device.

[0013] Furthermore, for the connection structure for a combined on-load tap-changer of the present utility model, the connection wires include a first connection wire and a second connection wire. The connection lead terminal and the wire fixing device are connected by the first connection wire, and the wire fixing device and the tap selector connection support are connected by the second connection wire. The connection lead terminal and the tap selector connection support are connected through the wire fixing device, so that the first connection wire and the second connection wire are respectively kept at an insulating level.

[0014] Furthermore, for the connection structure for a combined on-load tap-changer of the present utility model, the first connection wire is arranged in a V-shaped structure, and the second connection wire is arranged in a U-shaped or Z-shaped structure.

[0015] Furthermore, for the connection structure for a combined on-load tap-changer of the present utility model, the connection lead terminal includes a base and a connection rod. The connection rod is arranged on the base, and a wire connection hole corresponding to the connection wire is provided in the connection rod. The connection lead terminal is installed on the bottom bracket of the tap selector through the base, and the first connection wire is connected to the connection rod through the wire connection hole.

[0016] Furthermore, a connection structure for a combined on-load tap-changer according to the present utility model is adopted. The wire fixing device includes an insulating support and a wire groove provided on the top of the insulating support. The wire fixing device is installed on the bottom bracket of the tap selector through the insulating support. The first connection wire and the second connection wire are respectively connected to the insulating support through the wire groove.

[0017] Furthermore, a connection structure for a combined on-load tap-changer according to the present utility model is adopted. The tap selector connection support includes a support base, a support member, a fastening connection member, a connection pin, and a connection nut. The support member is provided as a cylindrical structure with an internal threaded hole. A guiding hole corresponding to the support member is provided on the cylindrical potential resistor. The support member is arranged in the guiding hole. The support base is installed on the cylindrical potential resistor through the fastening connection member passing through the support member. A through hole corresponding to the connection pin is provided in the support base, and a blind hole corresponding to the connection pin is provided on the cylindrical potential resistor. The connection pin passes through the through hole in the support base and is screwed into the blind hole on the cylindrical potential resistor to achieve the fixed connection between the support base and the cylindrical potential resistor. The second connection wire is connected to the support base in the tap selector connection support through the connection nut.

[0018] By adopting a connection structure for a combined on-load tap-changer according to the present utility model and using connection lead-out terminals, users only need to use bolts and nuts for fastening, which is convenient for operation and can avoid the situation that the connection lead-out end becomes loose and cannot be assembled due to user reasons. At the same time, when users assemble the cylindrical potential resistor, using the provided connection wires and wire fixing devices, it is convenient to fix and install the connection wires, ensuring that the connection wires are in an insulated state, and avoiding the problem that the insulation level of the connection wires cannot be guaranteed due to differences in user habits. In addition, when using the provided tap selector connection support, during the assembly process, users use fastening connection members and connection pins, and no aluminum chips will be generated, which can effectively avoid aluminum chips affecting the safe operation of the transformer, so as to meet the actual use requirements.

[0019] It can be seen that by adopting the connection structure according to the present utility model, through the improvement of the existing connection lead-out terminals, wire fixing devices, connection wires, and tap selector connection supports, it is not only convenient to connect and fix the connection wires, but also can keep the connection wires in an insulated state. And through the configured connection pins, no aluminum chips will be generated, which can effectively avoid aluminum chips affecting the safe operation of the transformer, so as to meet the actual use requirements. Its overall structure is simple, the operation is convenient, and it is suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 is the overall structure diagram during the installation of the existing connection structure;

[0022] Figure 2 is Figure 1 the top view of;

[0023] Figure 3 is the structure diagram of the existing connection lead terminal;

[0024] Figure 4 is the structure diagram of the existing connection wire;

[0025] Figure 5 is the structure diagram of the existing tap selector connection support;

[0026] Figure 6 is the overall structure diagram during the installation of the connection structure described in the present utility model;

[0027] Figure 7 is Figure 6 the top view of;

[0028] Figure 8 is the structure diagram of the connection lead terminal described in the present utility model;

[0029] Figure 9 is the structure diagram of the wire fixing device described in the present utility model;

[0030] Figure 10 is the structure diagram of the connection wire described in the present utility model Figure 1 ;

[0031] Figure 11 is the structure diagram of the connection wire described in the present utility model Figure 2 ;

[0032] Figure 12 is the structure diagram of the tap selector connection support described in the present utility model.

[0033] As shown in the figure: 1 - body of the cylindrical potentiometer resistor, 11 - cylindrical potentiometer resistor, 12 - bottom bracket of the tap selector, 2 - connection lead terminal, 21 - base, 22 - connection rod, 3 - wire fixing device, 31 - insulating support, 32 - wire groove, 4 - connection wire, 41 - first connection wire, 42 - second connection wire, 5 - tap selector connection support, 51 - support base, 52 - support member, 53 - fastening connection member, 54 - connection pin, 55 - connection nut. Detailed implementation manners

[0034] Next, embodiments of the present invention will be combined to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. Embodiment 1

[0035] As Figures 6 to 12 shown, this embodiment provides a connection structure for a combined on-load tap-changer, including a cylindrical potential resistor body 1. The cylindrical potential resistor body 1 includes a cylindrical potential resistor 11 and a tap selector bottom bracket 12. The connection structure further includes a connection lead terminal 2, a wire fixing device 3, a connection wire 4, and a tap selector connection support 5. Three tap selector connection supports 5 are installed on the cylindrical potential resistor 11, and three connection lead terminals 2 and wire fixing devices 3 are installed on the tap selector bottom bracket 12. The connection lead terminal 2, the wire fixing device 2, and the tap selector connection support 5 are connected by a connection wire 4, and the connection wire 4 is made to be at an insulating level through the wire fixing device 2. Among them, the connection wire 4 includes a first connection wire 41 and a second connection wire 42. The connection lead terminal 2 and the wire fixing device 3 are connected by the first connection wire 41, and the wire fixing device 3 and the tap selector connection support 5 are connected by the second connection wire 42. The connection lead terminal 2 and the tap selector connection support 5 are connected through the wire fixing device 3 to make the first connection wire 41 and the second connection wire 42 respectively in an insulating level state.

[0036] Furthermore, a connection structure for a combined on-load tap-changer described in this embodiment is adopted. The connection lead terminal 2 includes a base 21 and a connection rod 22. The connection rod 22 is arranged on the base 21, and a wire connection hole corresponding to the connection wire 4 is provided in the connection rod 22. The connection lead terminal 2 is installed on the bottom bracket 12 of the tap selector through the base 21, and the first connection wire 41 is connected to the connection rod 22 through the wire connection hole. The wire fixing device 3 includes an insulating support 31 and a wire groove 32 provided at the top of the insulating support 31. The wire fixing device 3 is installed on the bottom bracket 12 of the tap selector through the insulating support 31, and the first connection wire 41 and the second connection wire 42 are respectively connected to the insulating support 31 through the wire groove 32. The tap selector connection support 5 includes a support base 51, a support member 52, a fastening connection member 53, a connection pin 54, and a connection nut 55. The support member 52 is arranged as a cylindrical structure with an internal threaded hole. A guiding hole corresponding to the support member 52 is provided on the cylindrical potential resistor 11. The support member 52 is arranged in the guiding hole. The support base 51 is installed on the cylindrical potential resistor 11 through the fastening connection member 53 passing through the support member 52. A through hole corresponding to the connection pin 54 is provided in the support base 51, and a blind hole corresponding to the connection pin 54 is provided on the cylindrical potential resistor 11. The connection pin 54 passes through the through hole in the support base 51 and is screwed into the blind hole on the cylindrical potential resistor 11 to realize the fixed connection between the support base 51 and the cylindrical potential resistor 11. The second connection wire 42 is connected to the support base 51 in the tap selector connection support 5 through the connection nut 55. Embodiment 2

[0037] Since the connection wires used in the resistor are composed of three connection wires, and the two ends of the existing connection wires are formed by winding copper bars into loops. If the winding direction of the loop and the tightening direction of the nut are opposite, the copper bar loops will spread, which is not conducive to the connection of the wires.

[0038] Based on Embodiment 1, in this embodiment, to facilitate the user to perform connection and assembly by themselves, the existing three connection wires are improved, and a two-stage connection wire is adopted for connection and assembly. The connection wire 4 includes a first connection wire 41 and a second connection wire 42. Among them, the first connection wire 41 is arranged in a V-shaped structure, and the second connection wire 42 is arranged in a U-shaped or Z-shaped structure. Three first connection wires 41 and three second connection wires 42 are respectively provided. The specific structures of the three first connection wires 41 and the second connection wires 42 are as Figure 10 and Figure 11 shown. By using the provided first connection wire 41 and second connection wire 42, it is convenient for the user to perform connection and assembly by themselves.

[0039] It can be seen that by adopting the connection structure of the present utility model and utilizing the connection lead terminal 2, the user only needs to use bolts and nuts for fastening, which is convenient for operation and avoids the situation that the connection lead end becomes loose due to the user's reasons and cannot be assembled. At the same time, when the user assembles the cylindrical potentiometer resistor, by using the provided connection wire 4 and the wire fixing device 3, it is convenient to fixedly install the connection wire 4, ensuring that the connection wire is in an insulated state, avoiding the problem that the insulation level of the connection wire cannot be guaranteed due to the habitual differences of users. In addition, by using the provided tapping selector connection support 5, during the assembly process, when the user uses the fastening connection member 53 and the connection pin 54, no aluminum chips will be generated, which can effectively avoid the aluminum chips affecting the safe operation of the transformer, so as to meet the actual use requirements.

[0040] In summary, by adopting the connection structure of the present utility model, through the improvement of the existing connection lead terminal 2, the wire fixing device 3, the connection wire 4 and the tapping selector connection support 5, it is not only convenient to connect and fix the connection wire 4, but also enables the connection wire 4 to be in an insulated state. And through the configured connection pin 54, no aluminum chips will be generated, which can effectively avoid the aluminum chips affecting the safe operation of the transformer, so as to meet the actual use requirements. Its overall structure is simple, the operation is convenient, and it is suitable for popularization and application.

[0041] Other details not elaborated in the present utility model are all well-known conventional technologies in the art, so no detailed description is made.

[0042] The protection scope of the present utility model is not limited to the technical solutions disclosed in the specific embodiments. The above is only the preferred embodiment of the present utility model and does not limit the present utility model. Any minor modification, equivalent replacement and improvement made according to the technical solutions of the present utility model shall be included in the protection scope of the technical solutions of the present utility model.

Claims

1. A connection structure for a combined on-load tap-changer, comprising a cylindrical potential resistor body (1), the cylindrical potential resistor body (1) including a cylindrical potential resistor (11) and a bottom bracket (12) of a tap selector, characterized in that: The connection structure further includes connection lead terminals (2), wire fixing devices (3), connection wires (4), and tap selector connection supports (5). A plurality of tap selector connection supports (5) are installed on the cylindrical potentiometer resistor (11), and a plurality of connection lead terminals (2) and wire fixing devices (3) are installed on the bottom bracket (12) of the tap selector. The connection lead terminals (2), wire fixing devices (3), and tap selector connection supports (5) are connected by connection wires (4), and the connection wires (4) are kept in an insulated state through the wire fixing devices (3).

2. The connection structure for a combined on-load tap-changer according to claim 1, characterized in that: The connection wire (4) includes a first connection wire (41) and a second connection wire (42). The connection lead terminal (2) and the wire fixing device (3) are connected by the first connection wire (41), and the wire fixing device (3) and the tap selector connection support (5) are connected by the second connection wire (42). The connection lead terminal (2) and the tap selector connection support (5) are connected through the wire fixing device (3) to keep the first connection wire (41) and the second connection wire (42) in an insulated state respectively.

3. The connection structure for a combined on-load tap-changer according to claim 2, characterized in that: The first connection wire (41) is arranged in a V-shaped structure, and the second connection wire (42) is arranged in a U-shaped or Z-shaped structure.

4. A connection structure for a combined on-load tap-changer according to claim 2, characterized in that: The connection lead terminal (2) includes a base (21) and a connection rod (22). The connection rod (22) is arranged on the base (21), and a wire connection hole corresponding to the connection wire (4) is provided in the connection rod (22). The connection lead terminal (2) is installed on the bottom bracket (12) of the tap selector through the base (21), and the first connection wire (41) is connected to the connection rod (22) through the wire connection hole.

5. The connection structure for a combined on-load tap-changer according to claim 2, characterized in that: The wire fixing device (3) includes an insulating support (31) and a wire groove (32) arranged on the top of the insulating support (31). The wire fixing device (3) is installed on the bottom bracket (12) of the tap selector through the insulating support (31), and the first connection wire (41) and the second connection wire (42) are respectively connected to the insulating support (31) through the wire groove (32).

6. The connection structure for a combined on-load tap-changer according to claim 2, characterized in that: The tap selector coupling support (5) includes a support base (51), a support member (52), a fastening connector (53), a connecting pin (54) and a connecting nut (55). The support member (52) is arranged as a cylindrical structure with an internal threaded hole. A guiding hole corresponding to the support member (52) is provided on the cylindrical potentiometer resistor (11). The support member (52) is arranged in the guiding hole. The support base (51) is installed on the cylindrical potentiometer resistor (11) through the fastening connector (53) passing through the support member (52). A through hole corresponding to the connecting pin (54) is provided in the support base (51), and a blind hole corresponding to the connecting pin (54) is provided on the cylindrical potentiometer resistor (11). The connecting pin (54) passes through the through hole in the support base (51) and is screwed into the blind hole on the cylindrical potentiometer resistor (11) to realize the fixed connection between the support base (51) and the cylindrical potentiometer resistor (11). The second connecting wire (42) is connected to the support base (51) in the tap selector coupling support (5) through the connecting nut (55).

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