CN108631640B - Pulse driving source with variable output pulse width - Google Patents

Abstract

The invention discloses a pulse drive source with variable output pulse width, which sequentially includes five parts: a pulse forming unit, a main switch, a pulse transmission unit, an output diode and a magnetic switch with a coaxial structure. Wherein, the magnetic switch with coaxial structure is connected in parallel with both ends of the output diode, and is used to adjust the output pulse width at both ends of the diode. The invention solves the problem that the current pulse driving source cannot adjust the output pulse width, and has important value for expanding the application field of the pulse driving source.

Description

A Pulse Driving Source with Variable Output Pulse Width

technical field

The invention belongs to the technical field of pulse power and relates to a pulse driving source with variable output pulse width.

Background technique

A high-power pulse drive source is a type of device used to generate GW-level output pulse electric power. In practical applications, it is usually used to generate pulses with a certain pulse width (or half-width). There are various ways to generate high-power pulses, such as: Marx generator, pulse transformer (Pulse Transformer), pulse forming line (Pulse Forming Line), pulse forming network (Pulse Forming Network) and their mutual combination. Its basic feature is that once the device is constructed, its output pulse width is unique.

High-power pulse driving sources are widely used in military and civilian fields, such as the well-known application in driving high-power microwave sources to generate strong electromagnetic pulses, as well as in Z-pinch technology, detection and security inspection, industrial production inspection, material surface treatment And many other fields of industrial and agricultural production have a wide range of applications.

Driving and generating high-power microwaves is a typical application in the military field. The high-power pulse driving source injects tens of GW of electrical pulse energy into the high-power microwave source to drive and generate a high-current relativistic electron beam, and then the beam waves interact with each other. Function, output several GW level high power microwave.

In the civilian field, take the electric pulse crushing method as an example. The electric pulse fragmentation method uses the rapid expansion of the discharge spark channel inside the solid to generate a strong pressure wave, leading to the disintegration of the structure. Applied to in vitro treatment of urinary stones, gallstones, and regeneration of materials. The fragmentation effect depends on the accumulation of energy inside the structure, which is closely related to the duration of the discharge electric field, that is, depends on the pulse width.

As mentioned above, with the development of high-power pulse driving source technology, its application fields are constantly expanding, and the pulse width is an important technical index in practical applications. Limited by the structure and principle of the traditional high-power pulse driving source, the device only has a single output pulse width, which greatly limits its application range. In the research of high-power microwave sources, long pulses (about 100ns) and short pulses (about 30ns) are important research directions. In practical work, it is necessary to build two high-power pulse driving sources of completely different scales as their energy sources. The injection mechanism will lead to a huge cost of human, material and financial resources; the same is true in the civilian field, limited by the single output index of the high-power pulse drive source, it is difficult to obtain the comparison results under different parameters for the actual effect, and in order to obtain the desired effect , usually select parameters far above the action threshold for device design, resulting in a rough development.

Contents of the invention

In order to solve the problem that the traditional high-power pulse driving source can only output a single pulse width, resulting in high application cost, small range and inability to obtain ideal effects, the present invention proposes a high-power pulse driving source with the ability to continuously adjust the output pulse width , based on the existing high-power pulse drive source, adopts a parallel coaxial structure magnetic switch at the output end, and based on the precise reset technology of the magnetic core, realizes the precise control of the output pulse width. Not only can it solve practical problems encountered in scientific research and application, but it is also of great significance for saving energy and realizing green development.

The technical solution of the present invention is to provide a pulse driving source with variable output pulse width, which includes an outer cylinder, front end caps and tail end caps fixed at both ends of the outer cylinder, and a pulse coaxially arranged inside the outer cylinder in sequence along the length direction of the outer cylinder. The inner cylinder of the forming line and the inner cylinder of the transmission line; the adjacent ends of the inner cylinder of the pulse forming line and the inner cylinder of the transmission line are respectively provided with the cathode of the main switch and the anode of the main switch, and the other end of the inner cylinder of the transmission line is provided with the cathode of a diode; the special feature is that it also includes Connecting cylinder and annular magnetic core assembly; the above connecting cylinder is a good conductor;

The above-mentioned connecting cylinder is arranged coaxially inside the outer cylinder, and the open end of the connecting cylinder is in contact with the front end cover to realize electrical connection. There is an opening at the bottom of the connecting cylinder through which the inner cylinder of the transmission line passes through. Inside the barrel; the front end cover opposite to the diode cathode is provided with a diode anode;

The ring-shaped magnetic core assembly is set on the connecting cylinder, and the outer circular surface of the ring-shaped magnetic core assembly is in contact with the inner wall of the outer cylinder.

Preferably, the above annular magnetic core assembly includes a plurality of axially stacked annular magnetic cores, and there are gaps between adjacent magnetic cores.

Preferably, the pulse driving source further includes an insulating support for supporting the inner cylinder of the pulse forming line and the inner cylinder of the transmission line.

Preferably, the above-mentioned insulating support is ring-shaped, and a plurality of ring-shaped insulating supports are respectively located between the outer cylinder and the inner cylinder of the forming line, and between the outer cylinder and the inner cylinder of the transmission line.

Preferably, the cathode of the main switch is connected to the inner barrel of the forming line through threads, and the anode of the main switch and the cathode of the diode are connected to the inner barrel of the transmission line through threads.

Preferably, the diameter of the transmission line inner barrel is the same as the diameter of the pulse forming line inner barrel.

Preferably, the cathode of the main switch and the anode of the main switch are ball electrodes.

The magnetic switch composed of the connecting cylinder, the outer cylinder and the annular magnetic core assembly is connected in parallel at both ends of the diode cathode and the diode anode to form a line. The inner cylinder is charged with a certain voltage at the initial moment. The electrical pulse with a certain pulse width is output in between, and is transmitted to the diode cathode through the coaxial structure composed of the inner and outer cylinders of the transmission line, causing the diode cathode to explode and emit, forming a high-current electron beam with a certain pulse width; when the annular magnetic core component is not saturated, The pulse width of the high-current electron beam of the diode is basically equal to the pulse width of the line output; once the annular magnetic core component is saturated, the diode is short-circuited and extinguished, and the current is transmitted to the front end cover through the connecting cylinder to realize the adjustment of the pulse width of the high-current electron beam of the diode The saturation moment of the annular magnetic core assembly depends on its own reset state, and the reset state of the annular magnetic core assembly is controlled by the reset device at the saturation moment, and different reset states will result in different diode output pulse widths.

The beneficial effects of the present invention are:

1. In the pulse driving source with adjustable pulse width provided by the present invention, the output terminal is connected in parallel with the annular magnetic core assembly, and the output pulse width is adjusted by adjusting the reset point of the magnetic core, which fills the technical gap of the existing pulse driving source;

2. The annular magnetic core assembly of the present invention has extremely low saturation inductance, which can ensure a good output pulse waveform;

3. The present invention realizes the adjustment of different output pulse widths by adjusting the reset point of the magnetic core, which is different from the existing technical route in which the number of turns of the magnetic core winding is mechanically changed. This method is remotely controllable and does not require the device to be On-site disassembly and assembly.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic structural diagram of Embodiment 1.

The reference signs in the figure are: 1- forming the outer cylinder of the line, 2, 4- forming the insulating support of the inner cylinder of the line, 3- forming the inner cylinder of the line, 5- the cathode of the main switch, 6- the anode of the main switch, 7, 9- the inside of the transmission line Cylinder insulation support, 8-transmission line inner cylinder, 10-connecting cylinder, 11-ring core assembly, 12-diode cathode, 13-diode anode, 14-main switch outer cylinder, 15-transmission line outer cylinder, 16-diode outer Tube, 17-front end cover, 18-tail end cover.

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations.

As can be seen from Fig. 1, the present invention comprises outer cylinder, (outer cylinder is divided into and forms line outer cylinder 1, transmission line outer cylinder 15, main switch outer cylinder 14 and diode outer cylinder 16) end cover 18, forms line inner cylinder 3. Form the insulating support 2, 4 of the inner cylinder of the line, the cathode of the main switch 5, the anode of the main switch 6, the inner cylinder of the transmission line 8, the insulating support of the inner cylinder of the transmission line 7, 9, the diode cathode 12, the diode anode 13, the connecting cylinder 10, annular The magnetic core assembly 11 and the front end cover 17; the front end cover 17 and the rear end cover 18 are located at both ends of the outer cylinder, forming the line inner cylinder 3 and the transmission line inner cylinder 8 coaxially arranged inside the outer cylinder in sequence through insulating supports.

The main switch cathode 5 is connected to one end of the inner cylinder of the transmission line by thread, the main switch anode 6 is connected to one end of the transmission line inner cylinder 8 by thread, the diode cathode 12 is connected to the other end of the transmission line inner cylinder 8 by thread, and the diode anode 13 is connected to the front end of the transmission line. The cover 17 is electrically connected, the connecting cylinder 10 is electrically connected to the front end cover 17, and the annular magnetic core assembly 11 is located at the coaxial structure of the diode outer cylinder 16 and the connecting cylinder.

The above structure can be equivalent to include pulse forming unit A (composed of forming line outer cylinder 1, forming line inner cylinder 3, tail end cover 18, forming line inner cylinder insulating support 2, 4); main switch B (composed of main switch Outer cylinder 14, main switch cathode 5, main switch anode 6); pulse transmission unit C (composed of transmission line outer cylinder 15, transmission line inner cylinder 8, transmission line inner cylinder insulation support 7, 9); output diode unit D (composed of diode Cathode 12, diode anode 13, front end cover 17); coaxial structure magnetic switch E (made up of annular magnetic core assembly 11, diode outer cylinder 16, connecting cylinder 10) totally five parts.

The working principle is: the pulse forming unit A is initially charged with a certain voltage, and the energy is stored between the inner and outer cylinders in the form of an electric field at this time. When the charging voltage reaches the breakdown voltage of the main switch B, the main switch B is turned on to form a certain pulse width. The electric pulse is transmitted to the output diode unit D through the pulse transmission unit C, causing the cathode of the diode to explode and emit, generating a high-current electron beam, and bombarding the anode of the diode. The pulse width of the high-current electron beam is basically the same as the output pulse width of the forming line. The magnetic switch E of the coaxial structure is connected in parallel to both ends of the output diode unit D. Once the magnetic core is saturated, the diode is short-circuited and extinguished, and the current is transmitted to the front cover through the connecting cylinder to realize the adjustment of the pulse width of the high-current electron beam of the diode; the annular magnetic The saturation moment of the core component depends on its own reset state. The reset device controls the reset state of the magnetic core at the saturation moment. Different reset states will result in different diode output pulse widths.

Embodiment one

The following describes the embodiment of the pulse driving source applied to the 50-120 ns pulse width adjustment of the present invention. With reference to Fig. 2, be a kind of Tesla type pulse drive source with variable output pulse width, conical Tesla transformer 19 high-voltage end (left end) links to each other with forming line inner cylinder 3, transformer grounding end right end links to each other with forming line outer cylinder 1.

The glycerol medium is filled between the inner and outer cylinders of the pulse forming line unit, and its relative permittivity is about 43. When the physical length of the forming line is 3m, its electrical length can reach 120ns, which determines the upper limit pulse width that the driving source can output. The forming line uses a built-in Tesla transformer to charge it. The inner diameter of the formed wire outer cylinder is 400 mm, the outer diameter of the formed wire inner cylinder is 150 mm, and the formed wire output impedance is about 10 ohms. The main switch electrode is in the form of a ball head electrode, which works in self-breakdown mode. The pulse transmission line parameters are the same as the pulse forming line structure parameters, which are used to isolate the reflected pulse of the diode load.

The saturation of the core depends on the following formula:

The charging voltage is U _c (t), the saturation charging time of the magnetic core is t _s , here, it is also the width of the output pulse, S _m is the cross-sectional area of the magnetic core, and ΔB _max is the maximum magnetic induction intensity increment allowed by the magnetic core , whose value is equal to the difference between B _s and B _r , B _s and B _r are the saturation magnetic induction and residual magnetic induction of the magnetic material, N is the number of winding turns on the magnetic core, and K _T is the core filling factor. It can be seen that controlling ΔB _max is a direct way to control t _s , and the adjustment of ΔB _max can be realized through the magnetic core reset device. The approximate reset pulse is a triangular wave, and the output pulse of the driving source is a square wave. After calculation, assuming that the reset voltage is constant at 1kV and the output voltage is constant at 100kV, the corresponding reset time required for different output pulse widths is shown in Table 1.

Table 1 The corresponding table of reset time required for different output pulse widths

output pulse width reset time 50ns 10μs 60ns 12μs 70ns 14μs 80ns 16μs 90ns 18μs 100ns 20μs 110ns 22μs 120ns 24μs

It can be seen that by controlling the reset time of the magnetic core, different output pulse widths can be obtained. Obviously, the same effect can be achieved by controlling the reset voltage. Moreover, low-voltage/tens of μs-level reset devices are relatively mature technologies.

It can be seen that the high-power pulse driving source with continuously adjustable output pulse width has more important academic significance and practical application value, and is the only way for the further development of pulse power technology, but the existing devices have not been able to achieve a breakthrough in this performance.

Claims (7)

1. A pulse driving source with variable output pulse width, including an outer cylinder, a front end cover and a rear end cover fixed at both ends of the outer cylinder, and a pulse forming line coaxially arranged inside the outer cylinder along the length direction of the outer cylinder. The inner cylinder and the transmission line Inner cylinder; the adjacent ends of the inner cylinder of the pulse forming line and the inner cylinder of the transmission line are respectively provided with a main switch cathode and a main switch anode, and the other end of the transmission line inner cylinder is provided with a diode cathode; it is characterized in that it also includes a connecting cylinder and a ring magnetic core assembly ; The connecting cylinder is a good conductor; The connecting cylinder is arranged coaxially inside the outer cylinder, and the open end of the connecting cylinder is in contact with the front end cover to realize electrical connection. There is an opening at the bottom of the connecting cylinder for the inner cylinder of the transmission line to pass through. The inner cylinder of the transmission line passes through the opening so that the diode cathode is located at the Connect the inside of the barrel; the front end cover opposite to the diode cathode is provided with a diode anode; The annular magnetic core assembly is sleeved on the connecting cylinder, and the outer circular surface of the annular magnetic core assembly is in contact with the inner wall of the outer cylinder. 2. The pulse driving source with variable output pulse width according to claim 1, characterized in that: the annular magnetic core assembly comprises a plurality of axially stacked annular magnetic cores, and there is a gap between adjacent magnetic cores. gap. 3. The pulse driving source with variable output pulse width according to claim 2, further comprising an insulating support for supporting the inner cylinder of the pulse forming line and the inner cylinder of the transmission line. 4. The pulse driving source with variable output pulse width according to claim 3, characterized in that: the insulating support is ring-shaped, and a plurality of ring-shaped insulating supports are respectively located in the outer cylinder and the inner cylinder of the forming line, and in the outer cylinder and the transmission line between barrels. 5. The pulse driving source with variable output pulse width according to any one of claims 1-4, characterized in that: the cathode of the main switch is connected to the inner cylinder of the forming line through threads, and the anode of the main switch and the cathode of the diode are connected to the inner cylinder of the transmission line connected by threads. 6 . The pulse driving source with variable output pulse width according to claim 5 , wherein the diameter of the inner tube of the transmission line is the same as that of the inner tube of the pulse forming line. 7. The pulse driving source with variable output pulse width according to any one of claims 1-4, characterized in that: the cathode of the main switch and the anode of the main switch are ball electrodes.