Bridging combined type vacuum on-load tap-changer transition circuit

Abstract

The invention discloses a transition circuit of a bridging combined vacuum on-load tap-changer. The transition circuit is mainly composed of a U tap-changer selection side, an X tap-changer selection side, vacuum tubes V1-V4 and a transition resistor R. In the circuit, a group of odd-number-group moving contacts on a U tapping selection side are connected with the vacuum tubes V1 and V2 which are connected in parallel, and the other group of odd-number-group moving contacts are connected with the vacuum tubes V3 and V4 which are connected in parallel. The other ends of the vacuum tubes V2 and V3 are respectively connected with the other ends of the vacuum tubes V1 and V4 through a transition resistor R, and then are connected with the double-array moving contacts on the X tapping selection side; four vacuum tubes are adopted, V1 and V4 serve as main vacuum tubes, V2 and V3 serve as transition vacuum tubes, and mechanical contacts are replaced. Due to the innovative design, the circuit can adapt to various environments, and the problem that a mechanical contact is easily influenced by external factors such as dust and low temperature is effectively avoided. And meanwhile, the maintenance is more convenient, and the maintenance cost and frequency are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of switches, in particular to a transition circuit of a jumper combined vacuum on-load tap changer. Background Art

[0002] Vacuum on-load tap changer is a new technology developed in recent decades. When the on-load tap changer is on-load voltage regulation, the original transition contact is replaced by a vacuum tube, and the arc only occurs in the vacuum tube. For oil-immersed tap changers, it will not pollute the transformer oil in the switch, nor will it produce ablated metal particles. This can make the switch maintenance-free, saving a lot of manpower and material consumption. For dry tap changers, it can reduce the impact of the external environment on the switch, and can greatly reduce the maintenance frequency.

[0003] Traditional dry vacuum on-load tap changers often use two vacuum tubes and two mechanical contacts to complete the switching task. However, mechanical contacts are easily affected by external factors, such as dust and low temperature. A layer of conductive paste is applied to the mechanical contacts. If regular maintenance is not performed, dust and sand will easily adhere to the surface of the conductive paste, affecting the contact resistance and causing the contact resistance to increase. Over a long period of time, the temperature of the mechanical contacts will rise too high, causing the switch to burn out. In addition, in a low temperature environment, if the conductive paste adheres to dust and ice, the resistance of the mechanical switching contacts will increase, and it may not be possible to switch or switch in place, which will cause the switch to burn out. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the embodiments of the present application propose a jumper combined vacuum on-load tap changer transition circuit to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A transition circuit of a jumper combined vacuum on-load tap changer includes a U tap selection side, an X tap selection side, a vacuum tube V1, a vacuum tube V2, a vacuum tube V3 and a vacuum tube V4, and a transition resistor R. A group of single-group moving contacts on the U tap selection side is connected to the vacuum tube V1 and the vacuum tube V2, and the vacuum tube V1 and the vacuum tube V2 are connected in parallel; another group of single-group moving contacts on the U tap selection side is also connected to the vacuum tube V3 and the vacuum tube V4, and the vacuum tube V3 and the vacuum tube V4 are connected in parallel; the other end of the vacuum tube V2 is connected to the transition resistor R and the other end of the vacuum tube V1, and then connected to a group of double-group moving contacts on the X tap selection side; the other end of the vacuum tube V3 is connected to the transition resistor R and the other end of the vacuum tube V4, and then connected to another group of double-group moving contacts on the X tap selection side.

[0006] As a further technical solution of the present invention: a mechanical contact A is connected in parallel to the circuit of the vacuum tube V1.

[0007] As a further technical solution of the present invention: a mechanical contact B is connected in parallel to the circuit of the vacuum tube V4.

[0008] Beneficial effects: Compared with the existing technology, the beneficial effects of the present invention are: the present invention uses 4 vacuum tubes, of which V1 and V4 are 2 main vacuum tubes, and the other 2 transition vacuum tubes V2 and V3 replace the mechanical contacts; this can avoid the increase of mechanical switching contact resistance, which may cause the problem of failure to switch or inadequate switching. Maintenance is also more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of the switch working position in gear 1.

[0010] Figure 2 This is a schematic diagram of the switch working position in gear 2.

[0011] Figure 3 The tap selector switches from position 2 to position 4.

[0012] Figure 4 This is a schematic diagram of the vacuum tube V4 being disconnected.

[0013] 图5是真空管V2接通，产生环流IC的示意图。

[0014] Figure 6 It is a schematic diagram in which vacuum tube V1, vacuum tube V3 and vacuum tube V4 are all disconnected.

[0015] Figure 7 It is a schematic diagram in which both vacuum tube V3 and vacuum tube V4 are disconnected.

[0016] Figure 8 yes Figure 3-Figure 7 Switching waveform diagram under state process.

[0017] Fig. 9 This is the circuit diagram after adding mechanical contacts.

[0018] Fig.10 for Fig. 9 Switching waveform diagram under the status. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] like Figure 1As shown, a transition circuit of a jumper combined vacuum on-load tap changer includes a U tap selection side, an X tap selection side, a vacuum tube V1, a vacuum tube V2, a vacuum tube V3 and a vacuum tube V4, and a transition resistor R. A group of single-group moving contacts on the U tap selection side is connected to the vacuum tube V1 and the vacuum tube V2, and the vacuum tube V1 and the vacuum tube V2 are connected in parallel, another group of single-group moving contacts on the U tap selection side is also connected to the vacuum tube V3 and the vacuum tube V4, and the vacuum tube V3 and the vacuum tube V4 are connected in parallel, the other end of the vacuum tube V2 is connected to the transition resistor R and the other end of the vacuum tube V1, and then connected to a group of double-group moving contacts on the X tap selection side, the other end of the vacuum tube V3 is connected to the transition resistor R and the other end of the vacuum tube V4, and then connected to another group of double-group moving contacts on the X tap selection side.

[0021] The tap changer positions are shown in the following table: from Figure 1 and Figure 2 As can be seen from the figure, the switch consists of two parts: the tap selector and the diverter switch. So it is called a combined tap changer.

[0022] Here’s how it works: The following describes the tap change process of the switch from operating position 2 to position 3.

[0023] The load current is output from tap 3 through vacuum tube V4 and tap 2. A single-array moving contact of the selector moves from position 1 to position 3 without load, and a double-array moving contact of the selector moves from position 2 to position 4 without load. Figure 3 As shown: After the tap selection is completed, the transfer switch is released through the energy storage mechanism, causing the transfer switch vacuum tube to switch according to the following procedure.

[0024] 第一步：真空管V4断开，负载电流IN通过真空管V3和过渡电阻R输出。

[0025] 第二步：真空管V2接通，切换开关处于中间桥接状态，负载电流经双电阻和真空管V3、V2输出。级电压在桥接回路产生环流IC。

[0026] Step 3: The vacuum tube V3 is disconnected, and the load current flows through the vacuum tube V2 and the single resistor R to be output.

[0027] Step 4: The vacuum tube V1 is turned on, and the load current is output through the vacuum tube V1. The switching is completed, and the switch works in gear 3.

[0028] For switching from gear 3 to gear 4, the switching procedure is similar to the above.

[0029] This circuit is a combined circuit structure, that is, after a set of contacts on the U tap selection side and the X tap selection side are selected without load, the switching circuit starts to switch according to the procedure shown in the figure below. The switching waveform is as follows Figure 8 shown.

[0030] Other variants, if mechanical contact A is connected in parallel to the vacuum tube V1 circuit, and mechanical contact B is connected in parallel to the vacuum tube V4 circuit, the needs of high current circuits can be met. The schematic diagram and waveform are as follows Fig. 9 and Fig.10 shown.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0032] In addition, it should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment have also been appropriately combined to form other implementation modes that are easy for those skilled in the art to understand.

Claims

1. A transition circuit of a jumper combined vacuum on-load tap changer, comprising a U tap selection side, an X tap selection side, a vacuum tube V1, a vacuum tube V2, a vacuum tube V3 and a vacuum tube V4, and a transition resistor R, characterized in that: A group of single-array moving contacts on the U tap selection side is connected to the vacuum tube V1 and the vacuum tube V2, and the vacuum tube V1 and the vacuum tube V2 are connected in parallel. Another group of single-array moving contacts on the U tap selection side is also connected to the vacuum tube V3 and the vacuum tube V4, and the vacuum tube V3 and the vacuum tube V4 are connected in parallel. The other end of the vacuum tube V2 is connected to the transition resistor R and the other end of the vacuum tube V1, and then connected to a group of double-array moving contacts on the X tap selection side. The other end of the vacuum tube V3 is connected to the transition resistor R and the other end of the vacuum tube V4, and then connected to another group of double-array moving contacts on the X tap selection side.

2. A jumper combined vacuum on-load tap changer transition circuit according to claim 1, characterized in that: A mechanical contact A is connected in parallel to the circuit of the vacuum tube V1.

3. A jumper combined vacuum on-load tap changer transition circuit according to claim 1, characterized in that: A mechanical contact B is connected in parallel to the circuit of the vacuum tube V4.

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