Multi-tap high-voltage intermediate transformer

Abstract

The invention provides a multi-tap high-voltage intermediate test transformer, which can improve the quality of a power supply so as to eliminate the partial discharge interference of test equipment and meet the test requirements of different power equipment products. Comprising an iron core, the outer side of the iron core is sequentially sleeved with a low-voltage winding, a high-voltage winding and a voltage regulating winding, a ground screen is arranged between the low-voltage winding and the high-voltage winding, and the space between every two of the low-voltage winding, the ground screen, the high-voltage winding and the voltage regulating winding is filled with insulating paperboards and insulating supporting strips; the high-voltage winding is divided into a first high-voltage winding and a second high-voltage winding, the first high-voltage winding and the second high-voltage winding are coaxially wound at intervals, the winding directions of the first high-voltage winding and the second high-voltage winding are different, and the first high-voltage winding and the second high-voltage winding are connected through a series-parallel connection change-over switch. Therefore, series-parallel connection switching between the first high-voltage winding and the second high-voltage winding is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of design and manufacture of special transformers, and in particular relates to a multi-tap high-voltage intermediate test transformer. Background Art

[0002] The intermediate transformer is an important device that provides test power for power equipment testing. With the expansion of long-distance power transmission technology and industrial scale of the power grid, power equipment is developing towards high voltage levels and large capacities. The original test equipment of power product manufacturers no longer meets the relevant test needs. In order to adapt to the needs of high voltage levels and capacity expansion, and to provide power equipment manufacturers with product testing support capabilities, the test voltage range provided by the original intermediate test transformer must be increased and the power provided must also be expanded to meet the test requirements for different power equipment products.

[0003] In addition, with the development of high voltage technology, partial discharge has received more and more attention from the power sector. The size of partial discharge largely determines the operating reliability of ultra-high voltage power equipment. However, the power sector has set smaller and smaller values ​​for partial discharge of power equipment, which has directly led to higher requirements for power quality in power equipment acceptance projects in order to eliminate interference factors from partial discharge of test equipment. Summary of the invention

[0004] In view of the above problems, the present invention provides a multi-tap high-voltage intermediate test transformer, which can improve the power quality, eliminate the partial discharge interference of the test equipment, and meet the test requirements for different power equipment products.

[0005] The present invention adopts the following technical scheme: a multi-tap high-voltage intermediate test transformer, comprising an iron core, wherein a low-voltage winding, a high-voltage winding, and a voltage regulating winding are sequentially mounted on the outer side of the iron core, a ground screen is arranged between the low-voltage winding and the high-voltage winding, and insulating cardboard and insulating stays are filled between each of the low-voltage winding, the ground screen, the high-voltage winding, and the voltage regulating winding; the high-voltage winding is divided into a first high-voltage winding and a second high-voltage winding, the first high-voltage winding and the second high-voltage winding are coaxially and wound at intervals, the first high-voltage winding and the second high-voltage winding have different winding directions, and the first high-voltage winding and the second high-voltage winding are connected by a series-parallel switching switch to realize series-parallel switching between the first high-voltage winding and the second high-voltage winding.

[0006] Furthermore, the copper foil parts at the upper and lower ends of the ground screen are higher than the upper and lower ends of the low-voltage winding, and the grounding end on the ground screen is connected to the grounding hole on the iron core through a grounding lead of the ground screen;

[0007] Furthermore, the first high-voltage winding and the second high-voltage winding are wound on the upper and lower parts of the same first cardboard tube, the first high-voltage winding is right-winding, and the second high-voltage winding is left-winding;

[0008] Furthermore, the voltage regulating winding is divided into a first voltage regulating winding and a second voltage regulating winding, and the first voltage regulating winding and the second voltage regulating winding are wound on the upper and lower parts of the same second cardboard tube;

[0009] Further, the upper part of the second high-voltage winding leads out a head-end high-voltage lead-out wire A1, and the lower part of the first high-voltage winding leads out a head-end high-voltage lead-out wire A2; the lower part of the second high-voltage winding leads out a tail-end high-voltage lead-out wire X1, and the upper part of the first high-voltage winding leads out a tail-end high-voltage lead-out wire X2; the head-end high-voltage lead-out wire A1 and the head-end high-voltage lead-out wire A2 are both led out through a lead-out forming angle ring, and the lead-out forming angle ring is installed in the middle of the first cardboard tube;

[0010] Further, the head end high voltage lead wire A1, the head end high voltage lead wire A2, the tail end high voltage lead wire X1, and the tail end high voltage lead wire X2 are respectively connected to the series-parallel switching switch, and the tail end high voltage lead wire X2 is connected to the tail end high voltage lead terminal on the series-parallel switching switch and then connected to the positive terminal of the tap switch, and the voltage is output through the positive terminal and negative terminal of the tap switch;

[0011] Furthermore, the insulating paperboard is divided into a first insulating paperboard, a second insulating paperboard, and a third insulating paperboard, and the insulating stays are divided into a first insulating stay, a second insulating stay, and a third insulating stay; the first insulating paperboard and the first insulating stay are placed between the low-voltage winding and the ground screen; the second insulating paperboard and the second insulating stay are placed between the ground screen and the high-voltage winding; the third insulating paperboard and the third insulating stay are placed between the high-voltage winding and the voltage regulating winding;

[0012] Furthermore, the thickness of the first insulating paperboard, the second insulating paperboard, and the third insulating paperboard is 1 mm to 3 mm; the thickness of the first insulating support bar, the second insulating support bar, and the third insulating support bar is 1 mm to 3 mm.

[0013] The beneficial effect of the present invention is that a ground screen is provided between the low-voltage winding and the high-voltage winding, which can reliably isolate the partial discharge interference waves between the voltage input side and the voltage output side windings, and the electric field is also adjusted from the electric field between the windings on both sides to a simple electric field to the ground, thereby eliminating the partial discharge interference of the test equipment to a great extent. At the same time, the first high-voltage winding and the second high-voltage winding are connected by a series-parallel switching switch, and a large voltage regulation range can be achieved by switching the series and parallel connection of the first high-voltage winding and the second high-voltage winding, thereby being able to meet the test requirements for different power equipment products and having good use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention;

[0015] Figure 2It is a connection diagram of the high voltage winding in the present invention. DETAILED DESCRIPTION

[0016] like Figure 1 , Figure 2 As shown, a multi-tap high-voltage intermediate test transformer of the present invention comprises an iron core 1, a low-voltage winding 2, a high-voltage winding, and a voltage regulating winding are sequentially mounted on the outer side of the iron core 1, a ground screen 3 is arranged between the low-voltage winding 2 and the high-voltage winding, and insulating paperboard and insulating stays are filled between the low-voltage winding 2, the ground screen 3, the high-voltage winding, and the voltage regulating winding; the high-voltage winding is divided into a first high-voltage winding 4 and a second high-voltage winding 5, and the first high-voltage winding 4 and the second high-voltage winding 5 have the same electrical parameters except for the different winding directions; the first high-voltage winding 4 and the second high-voltage winding 5 are coaxial and spaced apart. Winding, the winding directions of the first high-voltage winding 4 and the second high-voltage winding 5 are different. The first high-voltage winding 4 and the second high-voltage winding 5 are connected through a series-parallel switching switch 6 to realize the series-parallel switching between the first high-voltage winding 4 and the second high-voltage winding 5. When the first high-voltage winding 4 and the second high-voltage winding 5 are connected in series, the number of coil turns is twice that of when they are connected in parallel, thereby achieving the purpose of multi-level voltage output; when the input voltage on the low-voltage side is 10KV, and the first high-voltage winding 4 and the second high-voltage winding 5 are connected in series, and the tap switch 13 is in the most positive tap, the output voltage on the high-voltage side can reach 220KV.

[0017] The copper foil parts at the upper and lower ends of the ground screen 3 are higher than the upper and lower ends of the low voltage winding 2 , and the grounding end on the ground screen 3 is connected to the grounding hole on the iron core 1 through the ground screen grounding lead 7 .

[0018] The first high-voltage winding 4 and the second high-voltage winding 5 are wound on the upper and lower parts of the same first cardboard tube 8, the first high-voltage winding 4 is wound to the right, and the second high-voltage winding 5 is wound to the left; the voltage regulating winding is divided into a first voltage regulating winding 10 and a second voltage regulating winding 11, and the first voltage regulating winding 10 and the second voltage regulating winding 11 are wound on the upper and lower parts of the same second cardboard tube 9.

[0019] The first end high voltage lead wire A1 is led out from the upper part of the second high voltage winding 5, and the first end high voltage lead wire A2 is led out from the lower part of the first high voltage winding 4; the tail end high voltage lead wire X1 is led out from the lower part of the second high voltage winding 5, and the tail end high voltage lead wire X2 is led out from the upper part of the first high voltage winding 4; the first end high voltage lead wire A1 and the first end high voltage lead wire A2 are both led out through the lead wire forming angle ring 12, and the lead wire forming angle ring 12 is installed in the middle part of the first cardboard tube 8; the first end high voltage lead wire A1 and the first end high voltage lead wire Line A2, tail end high voltage lead line X1, and tail end high voltage lead line X2 are respectively connected to the series-parallel switching switch 6, and the tail end high voltage lead line X2 is connected to the tail end high voltage lead end on the series-parallel switching switch 6 and then connected to the positive end of the tap switch 13, and the voltage is output through the positive end and negative end of the tap switch 13; wherein, the series-parallel switching switch 6 and the tap switch 13 are both existing switch devices, and the voltage can be adjusted and output through the tap switch 13.

[0020] The insulating paperboard is divided into a first insulating paperboard 14, a second insulating paperboard 15, and a third insulating paperboard 16, and the insulating stays are divided into a first insulating stay 17, a second insulating stay 18, and a third insulating stay 19; the first insulating paperboard 14 and the first insulating stay 17 are placed between the low-voltage winding 2 and the ground screen 3; the second insulating paperboard 15 and the second insulating stay 18 are placed between the ground screen 3 and the high-voltage winding; the third insulating paperboard 16 and the third insulating stay 19 are placed between the high-voltage winding and the voltage regulating winding; the thickness of the first insulating paperboard 14, the second insulating paperboard 15, and the third insulating paperboard 16 is 1 mm; the thickness of the first insulating stay 17, the second insulating stay 18, and the third insulating stay 19 is 1 mm.

[0021] The present invention provides a new intermediate test transformer for power equipment manufacturers, which is safe and reliable, has multiple voltage outputs, high voltage levels, low partial discharge, is easy to maintain, has a long service life, and can effectively reduce the partial discharge interference of the generator side power supply; by setting a ground screen 3, the partial discharge interference waves between the windings on the voltage input side (generator side) and the voltage output side (tested power equipment side) are reliably isolated, and the electric field is also adjusted from the electric field between the windings on both sides to a simple electric field to the ground, thereby eliminating the partial discharge interference of the test equipment to a great extent; and a large voltage regulation range is achieved by connecting two independent high-voltage winding coils in series and in parallel;

[0022] Specifically:

[0023] (1) Open the upper iron yoke 20 of the transformer and insert the lower iron yoke 21;

[0024] (2) According to the distance between the low-voltage winding 2 and the ground screen 3, first place the first insulating paperboard 14 outside the low-voltage winding 2, then evenly place the first insulating stays 17 of a certain thickness on the first insulating paperboard 14 according to the number of coils, and then insert the ground screen 3. The copper foil on the ground screen 3 should be higher than the upper and lower ends of the low-voltage winding 2 to achieve a shielding effect;

[0025] (3) The first high-voltage winding 4 and the second high-voltage winding 5 are wound on the upper and lower parts of the same first cardboard tube 8, so as to ensure the concentricity of the two high-voltage winding coils and facilitate assembly. According to the distance between the first high-voltage winding 4, the second high-voltage winding 5 and the ground screen 3, the second insulating cardboard 15 and the second insulating stay 18 are placed on the outside of the ground screen 3, and then the high-voltage winding is inserted;

[0026] (4) The first voltage regulating winding 10 and the second voltage regulating winding 11 are wound on the upper and lower parts of the same second cardboard tube 9, so as to ensure the concentricity of the two voltage regulating winding coils and facilitate assembly. According to the distance between the voltage regulating winding and the high-voltage winding, the third insulating paperboard 16 and the third insulating stay 19 are placed on the high-voltage winding, and then the voltage regulating winding is inserted;

[0027] (5) Install the outlet forming angle ring 12, assemble the upper iron yoke 20, install the iron yoke pad 22 on the upper iron yoke 20, and use the grounding lead wire 7 to connect the grounding end of the ground screen 3 to the grounding hole on the iron core 1 to ensure reliable grounding here.

[0028] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0029] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description 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 may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A multi-tap high voltage intermediate test transformer, comprising an iron core, wherein a low voltage winding, a high voltage winding and a voltage regulating winding are sequentially mounted on the outer side of the iron core, characterized in that: A ground screen is provided between the low-voltage winding and the high-voltage winding, and insulating cardboard and insulating stays are filled between the low-voltage winding, the ground screen, the high-voltage winding and the voltage regulating winding; the high-voltage winding is divided into a first high-voltage winding and a second high-voltage winding, the first high-voltage winding and the second high-voltage winding are coaxially and wound at intervals, the first high-voltage winding and the second high-voltage winding have different winding directions, and the first high-voltage winding and the second high-voltage winding are connected through a series-parallel switching switch to realize series-parallel switching between the first high-voltage winding and the second high-voltage winding.

2. A multi-tap high voltage intermediate test transformer according to claim 1, characterized in that: The copper foil parts at the upper and lower ends of the ground screen are higher than the upper and lower ends of the low-voltage winding, and the grounding end on the ground screen is connected to the grounding hole on the iron core through a grounding lead of the ground screen.

3. A multi-tap high voltage intermediate test transformer according to claim 1, characterized in that: The first high-voltage winding and the second high-voltage winding are wound on the upper and lower parts of the same first cardboard tube, the first high-voltage winding is right-winding, and the second high-voltage winding is left-winding.

4. A multi-tap high voltage intermediate test transformer according to claim 1, characterized in that: The voltage regulating winding is divided into a first voltage regulating winding and a second voltage regulating winding, and the first voltage regulating winding and the second voltage regulating winding are wound on the upper and lower parts of the same second cardboard tube.

5. A multi-tap high voltage intermediate test transformer according to claim 3, characterized in that: A head end high voltage lead wire A1 is led out from the upper part of the second high voltage winding, and a head end high voltage lead wire A2 is led out from the lower part of the first high voltage winding; a tail end high voltage lead wire X1 is led out from the lower part of the second high voltage winding, and a tail end high voltage lead wire X2 is led out from the upper part of the first high voltage winding; the head end high voltage lead wire A1 and the head end high voltage lead wire A2 are both led out through a lead forming angle ring, and the lead forming angle ring is installed in the middle of the first cardboard tube.

6. A multi-tap high voltage intermediate test transformer according to claim 5, characterized in that: The head end high voltage lead wire A1, the head end high voltage lead wire A2, the tail end high voltage lead wire X1, and the tail end high voltage lead wire X2 are respectively connected to the series-parallel switching switch, and the tail end high voltage lead wire X2 is connected to the tail end high voltage lead terminal on the series-parallel switching switch and then connected to the positive terminal of the tap switch, and the voltage is output through the positive terminal and negative terminal of the tap switch.

7. A multi-tap high voltage intermediate test transformer according to claim 1, characterized in that: The insulating paperboard is divided into a first insulating paperboard, a second insulating paperboard, and a third insulating paperboard, and the insulating stays are divided into a first insulating stay, a second insulating stay, and a third insulating stay; the first insulating paperboard and the first insulating stay are placed between the low-voltage winding and the ground screen; the second insulating paperboard and the second insulating stay are placed between the ground screen and the high-voltage winding; the third insulating paperboard and the third insulating stay are placed between the high-voltage winding and the voltage regulating winding.

8. A multi-tap high voltage intermediate test transformer according to claim 7, characterized in that: The thickness of the first insulating paperboard, the second insulating paperboard and the third insulating paperboard is 1 mm to 3 mm; the thickness of the first insulating support bar, the second insulating support bar and the third insulating support bar is 1 mm to 3 mm.

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