CN108565101B

CN108565101B - All-solid-state light 100 kV-level pulse transformer and manufacturing method thereof

Info

Publication number: CN108565101B
Application number: CN201810291934.3A
Authority: CN
Inventors: 殷毅; 张天洋; 杨建华; 陈冬群; 闵亚飞; 张自成; 申倩倩
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2018-03-30
Filing date: 2018-03-30
Publication date: 2020-03-31
Anticipated expiration: 2038-03-30
Also published as: CN108565101A

Abstract

The invention provides an all-solid-state light 100 kV-level pulse transformer and a manufacturing method thereof, belonging to the technical field of pulse transformers. The secondary coil is wound on the inner cylinder of the transformer. The transformer outer cylinder is sleeved on the outer side of the transformer inner cylinder wound with the secondary coil, the primary coil I and the primary coil II are wound on the outer side of the transformer outer cylinder, and the starting ends of the primary coil I and the primary coil II are respectively led out through bolts and are connected through copper bars to form a primary coil input end. The invention does not need transformer oil insulation, has no magnetic core, and realizes the compact, all solid and light weight of the whole transformer. Compared with an oil-insulated transformer, the transformer has better environmental adaptability, such as performance at high and low temperatures.

Description

All-solid-state light 100 kV-level pulse transformer and manufacturing method thereof

Technical Field

The invention relates to the technical field of pulse transformers, in particular to an all-solid-state light 100 kV-level pulse transformer and a manufacturing method thereof.

Background

A transformer is an electromagnetic device that is based on faraday's law of electromagnetic induction and is capable of transferring electrical energy in one circuit to another circuit through a magnetic field. Pulse transformers are a special type of transformer which transforms not a continuous voltage but a pulsed voltage. In recent years, with the wide application of pulse power devices in the fields of medical treatment, food sterilization, high-power microwaves, high-energy lasers and the like, pulse transformers are widely researched as main boosting modules of the pulse power devices, are important devices for realizing high-voltage output, and have higher and higher requirements on the pulse transformers, such as the requirement of improving the energy efficiency of the transformers and reducing the use cost in the civil field; in the military field, pulse power devices applied to flying platforms such as unmanned aerial vehicles, airplanes or missiles are researched, and the transformer is required to have the advantages of small size, light weight, strong environmental adaptability, high efficiency and the like.

In order to improve the coupling coefficient and energy efficiency, the existing high-voltage pulse transformer is generally designed by adopting a closed magnetic core or an open magnetic core (Zhang Yu, Liu jin Liang, Cheng Xin Dynasty and the like), a high-voltage closed magnetic ring is used for small-sized pulse transformation, strong laser and particle beams are 2010,22(12): 3047-; in the experimental study of compact repetition frequency Tesla transformer type modulators, such as Yanghuanwu, Zhang Jiande and the like, strong laser and particle beams 2008,20(8): 1392-. In addition, the above-mentioned pulse transformer has a load of a pulse forming line, a line equivalent capacitance of only a few tenths to a few nanofarads, and a charging energy of only a few joules to a few hundreds of joules, so that the charging time of the transformer is short, usually less than 10 microseconds. However, in many applications, the equivalent capacitance of the load charged by the pulse transformer is in the order of microfarads, such as a Marx generator type load, a pulse forming network type load, and the like, at this time, the charging period of the transformer reaches tens of microseconds or even hundreds of microseconds, and the transmission energy reaches tens of kJ. In this case, the core weight is increased because the core operating point is not close to the saturation induction Bs in consideration of the magnetic saturation of the transformer core, and the effective cross-sectional area Se of the core is satisfied

Where Smin is the minimum effective cross-sectional area of the core, Δ B_maxIs the maximum variation of magnetic induction of the magnetic core and is slightly less than the saturation induction B of the magnetic material_S，U₀Charging the primary capacitor of the transformer with a voltage t_zThe charging time at which the maximum charging voltage is reached.

From the formula, it can be seen that an increase in the charging time will result in an increase in the cross-sectional area of the transformer core, so that the weight of the pulse transformer core alone in this case is greater than the sum of the weights of the rest of the transformer; in addition, due to the introduction of the magnetic core, in order to prevent high-voltage breakdown between the primary coil and the secondary coil, the interior of the transformer is usually insulated by transformer oil, a sealing ring and a corresponding compression screw design need to be considered for ensuring oil sealing of the transformer, and the weight of the transformer is obviously increased by the factors. According to a traditional transformer design method, the weight of a 100 kV-level pulse transformer is about 50kg after the design is finished, and the design method cannot adapt to the application scene required by a compact and light 100 kV-level transformer.

Based on the above analysis, it is necessary to develop a design of a 100kV grade all-solid-state light high-voltage pulse transformer to meet the needs of military and civil fields in new situations.

Disclosure of Invention

In order to solve the defects of the problems, the invention aims to provide an all-solid-state light 100 kV-level pulse transformer and a manufacturing method thereof, the transformer does not need an additional magnetic core, the whole transformer is encapsulated by insulating glue, transformer oil high-voltage insulating liquid is not needed, redundant screws and sealing baffles are not needed, the weight is only about 10kg, and the research can promote the application of the pulse transformer in the civil and military fields. The microwave source is mainly used in the technical fields of high-power pulse modulators, high-power microwave sources, food sterilization, medical treatment, environmental protection and the like.

In order to achieve the purpose, the invention provides an all-solid-state light 100 kV-level pulse transformer which comprises a transformer outer cylinder, a transformer inner cylinder, a high-voltage output end baffle, a high-voltage output end, a secondary coil, a primary coil input end, a primary coil I, a primary coil II, a primary common ground end and a low-voltage end baffle; the secondary coil is wound on the transformer inner cylinder, the transformer outer cylinder is sleeved on the outer side of the transformer inner cylinder wound with the secondary coil, the primary coil I and the primary coil II are wound on the outer side of the transformer outer cylinder, the starting ends of the primary coil I and the primary coil II are respectively led out through bolts and connected through copper bars to form a primary coil input end, and the tail ends of the primary coil I and the primary coil II are led out through bolts and connected through copper bars to form a primary common ground end; the high-voltage output end baffle is arranged at one end of the outer cylinder of the transformer, the high-voltage output end is arranged on the high-voltage output end baffle, and the low-voltage end baffle is arranged at the other end of the outer cylinder of the transformer.

In the above scheme, preferably, the secondary coil is tightly wound on the transformer inner cylinder by adopting an enameled wire, before the secondary coil is wound, the outer surface of the transformer inner cylinder is coated with insulating paint in advance, and after the winding is finished, the surface of the secondary coil is coated with the insulating paint again.

In the above scheme, preferably, the transformer outer cylinder is made of nylon or polymer insulating material, a rectangular spiral groove is arranged on the outer side of the transformer outer cylinder and used for fixing the primary coil i and the primary coil ii, and the turns of the spiral groove have an interval of more than 3mm and are used for insulating the primary coil i or the primary coil ii.

In the above scheme, it is preferable that the primary coil i and the primary coil ii are copper strips, and the primary coil i and the primary coil ii are fixedly wound in a groove on the outer side of the transformer outer cylinder.

In the above scheme, preferably, the high-voltage output end baffle is provided with N through holes at a position corresponding to a space between the secondary coil and the primary coil i, and the N through holes are used for filling insulating glue between the secondary coil and the primary coil i, wherein N is greater than or equal to 3, and N is a positive integer.

In the above solution, it is preferable that the low-voltage end baffle is made of an annular insulating material, a hollow circle is arranged in the center, the outer diameter of the annular is consistent with the outer diameter of the transformer outer cylinder, and the inner diameter of the annular is smaller than the inner diameter of the transformer inner cylinder near the common ground end.

In the above scheme, it is preferable that both side end faces of the transformer outer cylinder and both side end faces of the transformer inner cylinder are provided with seal ring grooves, the seal rings are installed in the seal ring grooves, and in the glue pouring process, the insulating pouring glue is prevented from overflowing.

The transformer outer cylinder is characterized by also comprising a clamp plate I, a clamp plate II and a screw, wherein the clamp plate I and the clamp plate II are arranged into stainless steel circular rings, the diameter of each circular ring is larger than that of the transformer outer cylinder, a screw hole is designed on the circumference of each circular ring, annular bosses are arranged on the clamp plate I and the clamp plate II, N through holes are arranged on the clamp plate I, N is not less than 3, N is a positive integer, and the through holes correspond to glue filling through holes in a high-voltage output end baffle; two ends of the screw rod are respectively arranged on screw rod holes of the clamp plate I and the clamp plate II and are tensioned.

A manufacturing method of an all-solid-state light 100 kV-level pulse transformer comprises the following steps:

step 1, finishing winding a secondary coil in an inner cylinder of a transformer, finishing winding a primary coil I and a primary coil II in an outer cylinder of the transformer, finishing connection of an input end, a primary common ground end and a high-voltage output end of the primary coil, and sleeving an outer cylinder of the transformer on the outer side of the inner cylinder of the transformer wound with the secondary coil;

step 2, placing the low-voltage end baffle above the fixture plate II, fixing the position of the low-voltage end baffle through a boss of the fixture plate II, and vertically placing the primary and secondary stages of the transformer manufactured in the step 1 on the low-voltage end baffle (9);

step 3, sequentially placing a high-pressure output end baffle and a clamp plate I above the high-pressure output end baffle;

step 4, the screw rod penetrates through screw holes of the clamp plate I and the clamp plate II and is tightened, so that sealing rings at two ends of the transformer are well sealed;

step 5, placing the transformer manufactured in the step 4 in a vacuum environment for more than 5 hours, and then pouring the heated insulating glue into the transformer through a small hole in a high-voltage output end baffle;

step 6, taking out the transformer in the vacuum container after the insulating glue is completely cured;

and 7, dismantling the screw rod and removing the clamp to finish the manufacture of the all-solid-state 100 kV-level transformer.

The insulating glue in the step 5 is high-pressure-resistant insulating glue with good high-temperature fluidity, so that no air bubble is generated in the middle of the transformer in the glue filling process; in the design of the transformer, the insulation distance between the primary and secondary sides of the transformer is reduced under the condition that the insulation distance meets the requirement, so that the coupling coefficient of the transformer is further improved; and 5, in the sealing and glue filling process, heating and vibration can be combined, so that bubbles in the transformer can be conveniently removed.

The invention has the following beneficial effects:

the transformer does not need transformer oil insulation, does not have a magnetic core, and realizes compactness, all solid state and light weight; compared with an oil-insulated transformer, the transformer has better environmental adaptability, such as performance at high and low temperatures; and a special clamp is designed, so that the transformer is simple in manufacturing process and convenient to install.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a block diagram of the apparatus of the present invention;

FIG. 2 is a schematic diagram of the transformer clamp of the present invention;

FIG. 3 is a schematic diagram of the external structure of the all-solid-state transformer according to the present invention;

fig. 4 is a diagram of the output voltage and current waveforms of the transformer of the present invention.

Reference numbers in the figures: the transformer comprises a transformer outer cylinder 1, a transformer inner cylinder 2, a high-voltage output end baffle 3, a high-voltage output end 4, a secondary coil 5, a primary coil input end 6, a primary coil I7-1, a primary coil II 7-2, a primary coil II 8 and a secondary common ground end 9, a low-voltage end baffle 9, a clamp plate I10, a clamp plate II 11 and a screw rod 12.

Detailed Description

Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.

An all-solid-state light 100 kV-level pulse transformer is shown in figure 1 and comprises a transformer outer cylinder 1, a transformer inner cylinder 2, a high-voltage output end baffle 3, a high-voltage output end 4, a secondary coil 5, a primary coil input end 6, a primary coil I7-1, a primary coil II 7-2, a primary and secondary common ground end 8 and a low-voltage end baffle 9. The transformer does not need an external magnetic core, the whole transformer is encapsulated by insulating glue, transformer oil high-voltage insulating liquid is not needed, redundant screws and sealing baffles are not needed, the weight is only about 10kg, and the research can promote the application of the pulse transformer in the civil and military fields.

The secondary coil 5 is wound on the transformer inner cylinder 2, and the transformer outer cylinder 1 is sleeved on the outer side of the transformer inner cylinder 2 wound with the secondary coil 5. The primary coil I7-1 and the primary coil II 7-2 are wound on the outer side of the transformer outer cylinder 1, and the starting ends of the primary coil I7-1 and the primary coil II 7-2 are respectively led out through bolts and connected through copper bars to form a primary coil input end 6. The tail ends of the primary coil I7-1 and the primary coil II 7-2 are led out through bolts and connected through copper bars to form a primary and secondary common ground end 8. The secondary coil 5 is tightly wound on the transformer inner cylinder 2 by adopting an enameled wire, before the secondary coil 5 is wound, the outer surface of the transformer inner cylinder 2 is coated with insulating paint in advance, and after the winding is finished, the surface of the secondary coil 5 is coated with the insulating paint again. The transformer outer cylinder 1 is made of nylon or high polymer insulating materials, a rectangular spiral groove is formed in the outer side of the transformer outer cylinder 1 and used for fixing a primary coil I7-1 and a primary coil II 7-2, and the turns of the spiral groove are spaced by more than 3mm and used for insulating the primary coil I7-1 or the primary coil II 7-2. The primary coil I7-1 and the primary coil II 7-2 are copper belts, and the primary coil I7-1 and the primary coil II 7-2 are fixedly wound in a groove in the outer side of the transformer outer cylinder 1. And the outer surface of the inner transformer barrel 2 is coated with epoxy glue insulating paint in advance, and the surface of the secondary coil 5 of the transformer is coated with epoxy glue insulating paint again after the winding is finished. The purpose of the transformer is to enhance the insulation between the primary and the secondary, and mainly to fix the secondary coil 5 of the transformer, so as to avoid the falling off of the secondary coil caused by the overlarge turn-to-turn electromotive force of the coil when the secondary coil passes thousands of amperes in a hundred microsecond charging period. Experiments show that when the transformer wound by the mode is used for pulse charging of high-voltage capacitance loads, the secondary coil can bear thousands of amperes of current and cannot scatter. In order to further reduce the primary loop impedance of the transformer and improve the efficiency of the transformer, the primary copper strips of the transformer are wound in parallel in two groups, the initial ends of the two groups of primary coils are led out of the outer cylinder of the transformer through copper screws, and the two groups of primary coils are connected in parallel outside the transformer through copper strips and serve as common ground ends. The tail ends of the two groups of primary coils are led out through copper screws and are connected in parallel outside the transformer to be used as a primary high-voltage input end of the transformer. Experimental surface through this kind of design, transformer primary copper strip still can normally work under the condition of passing through impulse current 100 kA.

The high-voltage output end baffle 3 is arranged at one end of the transformer outer cylinder 1. The high-voltage output end 4 is arranged on the high-voltage output end baffle 3. And a low-voltage end baffle 9 is arranged at the other end of the transformer outer cylinder 1. The high-voltage output end baffle is provided with a copper screw rod at the center, is connected with the secondary output of the transformer and is used as the high-voltage output end of the transformer; the output end baffle of the transformer is provided with N (N is more than or equal to 3) through holes at the position corresponding to the space between the primary and secondary sides of the transformer, and is used for filling insulating glue between the primary and secondary sides of the transformer. The low-voltage output end baffle is made of annular insulating materials, the outer diameter of the ring is consistent with that of the outer cylinder of the transformer, and the inner diameter of the ring is slightly smaller than that of the part, close to the common ground, of the inner cylinder of the transformer. The transformer inner cylinder and the transformer outer cylinder are provided with sealing ring grooves on two sides and are provided with sealing rings. In the process of pouring the glue into the transformer, the insulating pouring glue is prevented from overflowing. And insulating glue is adopted between the primary and secondary transformer surfaces for insulating and encapsulating. In order to glue the all-solid-state transformer, a set of clamp is specially manufactured. The high-voltage output end baffle 3 is provided with N through holes at the position corresponding to the space between the secondary coil 5 and the primary coil I7-1, and the through holes are used for filling insulating glue between the secondary coil 5 and the primary coil I7-1 and the primary coil II 7-2, wherein N is not less than 3, and N is a positive integer. The low-voltage end baffle 9 is made of annular insulating material, a hollow circle is arranged in the center, the outer diameter of the ring is consistent with the outer diameter of the outer cylinder of the transformer, and the inner diameter of the ring is smaller than that of the part, close to the common ground, of the inner cylinder of the transformer. The sealing ring grooves are formed in the two end side faces of the transformer outer cylinder 1 and the two end side faces of the transformer inner cylinder 2, sealing rings are arranged in the sealing ring grooves, and in the glue pouring process, the insulating pouring glue is prevented from overflowing. The clamp comprises a clamp plate I10, a clamp plate II 11 and a screw 12. The fixture plate I10 and the fixture plate II 11 are arranged to be stainless steel circular rings, the diameter of each circular ring is larger than that of the outer cylinder of the transformer, screw holes are designed in the circumference of each circular ring, and annular bosses are arranged on the fixture plate I10 and the fixture plate II 11. N through holes are formed in the clamp plate I10, wherein N is larger than or equal to 3, and N is a positive integer. The through hole corresponds to the glue filling through hole on the high-voltage output end baffle 3. Two ends of the screw 12 are respectively arranged on screw holes of the clamp plate I10 and the clamp plate II 11 and are arranged in a tensioning mode.

The maximum diameter of the outer cylinder of the transformer is 230mm, the axial length of the outer cylinder of the transformer is 230mm, the primary of the transformer is wound by a copper strip with the width of 12mm and the thickness of 2mm, 5.5 turns are provided, and the inductance is 5.2 muH after the two primary are connected in parallel.

The secondary transformer is formed by densely winding enamelled wires with the diameter of 1mm on the outer surface of the conical inner transformer cylinder, the number of turns is 190, the outer radiuses of two ends of the conical inner transformer cylinder are respectively 90mm and 100mm, and the actual measurement of the secondary transformer is 4.2 mH. Under the condition of not adding a magnetic core, the transformer coupling coefficient is measured to be 0.87, and the transformer transformation ratio is measured to be 24.

The designed transformer clamp is two stainless steel circular rings, referring to fig. 2, namely a high-voltage end clamp 1 and a low-voltage end clamp 2, the high-voltage end circular ring and the low-voltage end circular ring are both provided with positioning bosses, the outer part of each circular ring is 280mm in diameter, a transformer is placed between the two clamps, high-voltage end baffles and low-voltage end baffles of the transformer are pressed tightly through screws, the encapsulation of the transformer is completed according to the manufacturing method, and the total weight of the transformer with the highest withstand voltage of 120kV is only 11kg after the clamps are removed.

To verify the characteristics of the examples, experimental verification was performed according to the design. Selecting a transformer primary capacitor Cp of 1.2mF, an initial charging voltage of 5kV and a transformer secondary capacitor of 1 muF, and measuring the highest voltage of 120kV on a load capacitor through experiments, wherein the corresponding charging time is 82 mus, the maximum primary current of the transformer is 85kA, the maximum secondary current of the transformer is 2.25kA and the transmission energy is 7.2 kJ; the transformer has good working performance. The voltage at the secondary output of the transformer and the transformer primary current waveform are shown in fig. 4.

The 100 kV-level all-solid-state pulse transformer device disclosed by the invention has the advantages that the additional magnetic core is not needed, the transformer oil insulation is not needed, the all-solid state is realized, the structure is compact, the weight is only 10kg, and the weight and the volume of the traditional 100 kV-level pulse transformer are greatly reduced. Meanwhile, the transformer has a wider temperature working range due to the fact that the transformer is in an all-solid state. The all-solid-state light pulse transformer is simple in structure, reasonable in design and convenient to use, and has important significance for promoting wide application of the transformer in the military and civil fields.

step 1, finishing winding a secondary coil 5 on an inner transformer cylinder 2, finishing winding a primary coil I7-1 and a primary coil II 7-2 on an outer transformer cylinder 1, respectively finishing connection of an input end 6 of the primary coil, a common ground end 8 of the primary coil and a high-voltage output end 4, and sleeving the outer transformer cylinder 1 on the outer side of the inner transformer cylinder 2 wound with the secondary coil 5. In the design of the transformer, the insulation distance between the primary and secondary sides of the transformer is reduced under the condition that the insulation distance meets the requirement, so that the coupling coefficient of the transformer is further improved. The primary input of the transformer is introduced by adopting low inductance, the influence of stray parameters is reduced, and the energy efficiency is improved.

And 2, placing the low-voltage end baffle 9 above the fixture plate II 11, fixing the position of the low-voltage end baffle 9 through a boss of the fixture plate II 11, and vertically placing the primary and secondary stages of the transformer manufactured in the step 1 on the low-voltage end baffle (9).

And 3, sequentially placing a high-voltage output end baffle 3 and a clamp plate I10 above the high-voltage output end baffle.

And 4, penetrating the screw 12 through screw holes of the clamp plate I10 and the clamp plate II 11, and tensioning to ensure that sealing rings at two ends of the transformer are well sealed. The high-voltage output end of the transformer adopts an inwards concave structural design, and referring to fig. 1, the axial length of the transformer is reduced, and the structure is more compact. And 5, placing the transformer manufactured in the step 4 in a vacuum environment for more than 5 hours, and then pouring the heated insulating glue into the transformer through the small holes in the high-voltage output end baffle 3. The insulating glue with high pressure resistance and good high-temperature fluidity is selected as the insulating glue, so that no air bubble is generated in the middle of the transformer in the glue pouring process. In the process of sealing and glue filling, heating and vibration can be combined, so that bubbles in the transformer can be conveniently removed.

And 6, taking out the transformer in the vacuum container after the insulating glue is completely cured.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A manufacturing method of an all-solid-state light 100 kV-level pulse transformer is characterized by comprising the following steps:

step 1, winding a secondary coil (5) on an inner transformer cylinder (2), winding a primary coil I (7-1) and a primary coil II (7-2) on an outer transformer cylinder (1), respectively mounting a primary coil input end (6), a primary and secondary common ground end (8) and a high-voltage output end (4), and sleeving the outer transformer cylinder (1) on the outer side of the inner transformer cylinder (2) wound with the secondary coil (5);

step 2, placing the low-voltage end baffle (9) above the fixture plate II (11), fixing the position of the low-voltage end baffle (9) through a boss of the fixture plate II (11), and vertically placing the primary and secondary stages of the transformer manufactured in the step 1 on the low-voltage end baffle (9);

step 3, sequentially placing a high-pressure output end baffle (3) and a clamp plate I (10) above; the clamp plate I (10) and the clamp plate II (11) are arranged to be stainless steel circular rings, and the diameters of the circular rings are larger than that of the outer cylinder of the transformer; the clamp plate I (10) and the clamp plate II (11) are respectively provided with an annular boss;

step 4, the screw rod (12) penetrates through screw holes of the clamp plate I (10) and the clamp plate II (11) and is tightened, so that sealing rings at two ends of the transformer are well sealed;

step 5, placing the transformer manufactured in the step 4 in a vacuum environment for more than 5 hours, and then pouring the heated insulating glue into the transformer through the small holes in the high-voltage output end baffle (3); the insulating glue in the step 5 is high-pressure-resistant insulating glue with good high-temperature fluidity, so that no air bubble is generated in the middle of the transformer in the glue filling process; in the design of the transformer, the insulation distance between the primary and secondary sides of the transformer is reduced under the condition that the insulation distance meets the requirement, so that the coupling coefficient of the transformer is further improved; step 5, in the sealing and glue filling process, heating and vibration can be combined, so that bubbles in the transformer can be conveniently removed;

step 7, dismantling the screw rod and removing the clamp to complete the manufacture of the all-solid-state 100 kV-level transformer; the transformer does not need an external magnetic core.