A Tesla pulse transformer with no supporting frame for the secondary coil

Abstract

The present invention discloses a Tesla pulse transformer with a secondary coil without a supporting frame, which comprises an outer cylinder, two left and right middle opening insulators for supporting an inner cylinder, an outer magnetic core coaxially arranged inside the outer cylinder, a primary coil, an inner magnetic core and an inner cylinder, and a conical secondary coil suspended in insulating oil. The present invention solves the problem that the burrs and micro-protrusions introduced by the secondary coil support of the existing Tesla pulse transformer are prone to discharge breakdown or even failure, greatly simplifies the structure of the megavolt Tesla pulse transformer, and is of great significance for improving the operating reliability and life of the megavolt Tesla pulse transformer. The invention also has important reference value for high-voltage transformers in the civilian field.

Description

Technical Field

[0001] The invention belongs to the technical field of pulse power, and relates to a Tesla pulse transformer with a secondary coil without a supporting frame. Background Art

[0002] Tesla pulse transformer is a pulse boost converter widely used in pulse power technology. It is mainly used in pulse drive sources to boost voltage and obtain secondary high voltage output above megavolt level, which is used to charge the pulse forming line or discharge to a specific load. Tesla pulse transformer has obvious advantages such as simple principle, compact structure and high boost efficiency.

[0003] In actual use, the secondary of Tesla pulse transformer is usually wound with fine copper wire, with more than 1000 turns. Due to the weight of the copper wire itself, in order to maintain its coaxiality, the copper wire is usually wound on a support frame. Commonly used support frames include nylon frames and electrical paperboard frames, among which the electrical paperboard frame is the most widely used because it can achieve a relative dielectric constant close to that of transformer oil after being immersed in transformer oil, thereby avoiding the field concentration caused by the use of nylon frames. However, in the actual use of electrical paperboard frames, it was found that burrs are easily generated on the surface of electrical paperboard, and glue is required to be used for bonding when the thin copper wire is fixed to the surface of electrical paperboard, resulting in a large number of burrs and microscopic protrusions on the secondary surface of the Tesla transformer composed of electrical paperboard and thin copper wire. These burrs and microscopic protrusions are very likely to cause discharge breakdown in the case of megavolt voltage, and in severe cases, the copper wire will break, causing the entire device to fail and cause irreversible damage. Summary of the invention

[0004] In order to solve the problem that the secondary coil of the traditional Tesla pulse transformer is prone to discharge breakdown or even failure due to the use of a supporting frame, and at the same time follow the basic principle that the structure should be as simple as possible in high-voltage situations, the present invention proposes a Tesla pulse transformer with a secondary coil without a supporting frame, aiming to simplify the secondary coil of the megavolt Tesla pulse transformer, reduce the introduction of stray parameters, and at the same time improve the overall reliability of the transformer to achieve long-life trouble-free operation.

[0005] The present invention adopts a hollow metal tube with a density close to that of transformer oil as the secondary winding, so that the secondary coil can be suspended in the transformer oil, thereby eliminating the support frame of the secondary coil, greatly simplifying the transformer structure and improving its reliability in high-voltage occasions.

[0006] The technical solution of the present invention is to provide a Tesla pulse transformer with a secondary coil without a supporting frame, comprising an outer cylinder, an outer magnetic core coaxially arranged inside the outer cylinder, a primary coil, an inner magnetic core and an inner cylinder, and also comprising two left and right middle opening insulators for supporting the inner cylinder;

[0007] Its special features are:

[0008] The conical secondary coil is also formed by winding a hollow metal wire on a special mold, wherein the inner radius r of the hollow metal wire used in the conical secondary coil is 内 With outer radius r 外 Should satisfy r 2 外 / r 2 内 =10 / 9; the hollow metal wire is a hollow copper tube or an aluminum tube, and the outer radius of the hollow copper tube is greater than 3mm; the hollow copper tube itself should have a certain strength so that it can ensure basic strength;

[0009] The high-voltage end and the low-voltage end of the conical secondary coil are connected to the inner cylinder and the outer cylinder respectively. The space between the inner cylinder and the outer cylinder is filled with insulating medium. The density of the conical secondary coil is close to the density of the insulating medium, ensuring that the conical secondary coil as a whole can be suspended in the insulating medium.

[0010] The outer cylinder is in contact with the outer magnetic core, and the inner cylinder is in contact with the inner magnetic core. The function of the magnetic core is to gather the magnetic field and improve the coupling efficiency. The primary coil is generally discharged through an external circuit, and the magnetic field generated by it is coupled to the secondary coil through the magnetic core, and the voltage is increased on the secondary coil. The large diameter end of the conical secondary coil is connected to the outer cylinder, and the small diameter end is connected to the inner cylinder. The high voltage output is located at the small diameter end, and the generated high voltage is coaxially output through the inner cylinder.

[0011] Furthermore, 45# transformer oil is used as the insulating medium.

[0012] Furthermore, both the outer magnetic core and the inner magnetic core use silicon steel sheets as magnetic core materials.

[0013] Furthermore, the outer cylinder and the inner cylinder are made of stainless steel.

[0014] Furthermore, the number of turns of the primary coil is 1, and a copper plate is used to install along the circumference of the outer magnetic core.

[0015] The beneficial effects of the present invention are:

[0016] 1. The Tesla pulse transformer with no secondary coil support frame provided by the present invention eliminates the need for electrical paperboard or nylon support frame of the secondary coil, reduces the introduction of stray parameters, and has high overall reliability and long service life of the transformer, which is the first in this field;

[0017] 2. The Tesla pulse transformer with a secondary coil without a supporting frame provided by the present invention greatly simplifies the structure of Tesla pulse transformers above the megavolt level and achieves zero introduction of non-functional components, which is of great significance for improving the stability and reliability of Tesla pulse transformers above the megavolt level. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] The reference numerals in the figure are: 1-outer cylinder, 2-outer magnetic core, 3-primary coil, 4-secondary coil, 5-inner magnetic core, 6-inner cylinder, 7, 8-two middle opening insulators for supporting the inner cylinder. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0021] Embodiment 1

[0022] from Figure 1 It can be seen that the present invention includes an outer cylinder 1, an outer magnetic core 2, a primary coil 3, a secondary coil 4, an inner cylinder 6, an inner magnetic core 5 and two left and right middle opening insulators 7 and 8 for supporting the inner cylinder, which are located at the left and right ends of the device to achieve overall support for the inner cylinder and ensure the coaxiality of the inner and outer cylinders.

[0023] The outer cylinder 1 and the inner cylinder 6 are formed by processing with stainless steel, and the primary coil 3 is installed along the circumference of the outer magnetic core 2 with a whole copper plate with a thickness of 1 mm, which is equivalent to the number of turns of the primary coil 3 being 1. The copper plate and the outer magnetic core 2 should be insulated. The outer magnetic core 2 and the inner magnetic core 5 are both stacked with 0.05 mm thin strip silicon steel to avoid eddy current loss and premature saturation.

[0024] In this embodiment, a hollow copper tube is used to wind the secondary coil 4. A special mold should be made, and the secondary coil 4 should be removed from the mold after winding. 45# transformer oil is used as the insulating medium, and its density is 895kg / m 3 , the density of copper is generally 8900kg / m 3 , which is about ten times that of transformer oil. After calculation, the inner radius r of the hollow copper tube used 内 With outer radius r 外 The following relationship should be satisfied:

[0025] r 2 外 / r 2 内 =10 / 9

[0026] The copper tube that meets this condition can be suspended in the transformer oil, so that the coaxiality can be ensured without support. The premise is that the copper tube itself has a certain structural strength. In this embodiment, a copper tube with an outer radius greater than 3 mm is selected.

[0027] A conical mold is made, and a hollow copper tube is used to wind the secondary coil on the mold, about 1,000 turns. After completion, the mold is peeled off as a whole and installed between the inner and outer cylinders. The large diameter end is connected to the outer cylinder for grounding, and the small diameter end is connected to the inner cylinder. The high voltage is coaxially output by the inner cylinder. Ideally, this transformer can achieve a 1,000-fold voltage increase.

Claims

1. A Tesla pulse transformer with a secondary coil without a supporting frame, comprising an outer cylinder, an outer magnetic core coaxially arranged inside the outer cylinder, a primary coil, an inner magnetic core and an inner cylinder, and also comprising two left and right middle opening insulators for supporting the inner cylinder; Features: The conical secondary coil is also formed by winding a hollow metal wire on a special mold, wherein the inner radius r of the hollow metal wire used in the conical secondary coil is 内 With outer radius r 外 Should satisfy r 2 外 / r 2 内 =10 / 9; the hollow metal wire is a hollow copper tube or an aluminum tube; the outer radius of the hollow copper tube is greater than 3 mm; The high-voltage end and the low-voltage end of the conical secondary coil are connected to the inner cylinder and the outer cylinder respectively. The space between the inner cylinder and the outer cylinder is filled with insulating medium. The density of the conical secondary coil is close to the density of the insulating medium, ensuring that the conical secondary coil as a whole can be suspended in the insulating medium.

2. The Tesla pulse transformer with a secondary coil without a supporting frame according to claim 1, characterized in that: 45# transformer oil is used as the insulating medium.

3. The Tesla pulse transformer with a secondary coil without a supporting frame according to claim 1, characterized in that: Both the outer magnetic core and the inner magnetic core use silicon steel sheets as the magnetic core material.

4. The Tesla pulse transformer with a secondary coil without a supporting frame according to claim 1, characterized in that: The outer cylinder and the inner cylinder are made of stainless steel.

5. The Tesla pulse transformer with a secondary coil without a supporting frame according to claim 1, characterized in that: The number of turns of the primary coil is 1, and a copper plate is used to install it along the circumference of the outer magnetic core.

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