Flyback high-voltage direct-current power supply device based on positive polarity Marx circuit

Abstract

The invention belongs to the technical field of high-voltage direct-current power supplies, and particularly relates to a high-voltage direct-current power supply device based on a positive polarity Marx circuit and a flyback transformer. The high-voltage direct-current power supply device comprises an input alternating-current power supply, an alternating-current rectification module, a positive polarity Marx circuit, a flyback transformer and a post-stage rectification circuit, after an alternating current power supply is converted into direct current through the rectifier module, the direct current serves as charging input of the positive polarity Marx circuit. Through parallel charging and series discharging modes of the positive polarity Marx circuit, energy is transmitted to the flyback transformer to realize a flyback operation mode, and finally stable high-voltage direct current is output through the rectification circuit. According to the invention, the problem of cooperative operation between the positive polarity Marx circuit and the flyback transformer is solved; the improved Marx circuit structure not only provides higher output voltage, but also remarkably improves the power transmission efficiency and the voltage gain of the system, and meets the high-voltage direct current application requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of high - voltage DC power supplies, and particularly relates to a high - voltage DC power supply device. Background Art

[0002] With the development of electronic devices towards higher integration and smaller volume, power supply systems also need to have the characteristics of high power density and high frequency. A high - voltage DC power supply is a device that can provide a highly stable DC voltage in a short time and is widely used in multiple fields. In agriculture, it can be used for electrostatic atomization of liquids to eliminate pests, study the effects of static electricity on agricultural organisms, and conduct electrostatic treatment of seeds. In medical engineering, high - voltage DC power supply technology is applied to devices such as CT cameras and X - ray machines to generate the required high voltage in an extremely short time.

[0003] Pulse power technology, also known as high - power pulse technology, is a power - processing technology. Its core lies in accumulating energy for a long time and then releasing the energy to the load at an extremely high power density in an extremely short time through rapid compression and conversion. Its output characteristics are usually narrow - pulse high - voltage square waves, which have certain similarities with traditional switching power supplies. By optimizing this technology into a chopper circuit structure, it can be further applied to the field of switching - mode DC power supplies with high - voltage output. The present invention is an innovative result based on this technical direction. Summary of the Invention

[0004] The purpose of the present invention is to provide a high - voltage DC power supply device that can operate at high voltage, high frequency, and fast charge to overcome the deficiencies of existing high - voltage DC power supply devices.

[0005] The present invention proposes a high - voltage DC power supply device that organically combines a positive - polarity Marx circuit and a flyback transformer. Its structure includes: an input AC power supply, a rectifier circuit, a charging control module, a positive - polarity Marx circuit module (i.e., a positive - polarity single - bridge - arm Marx circuit), a flyback transformer, and a flyback rectifier output module. Among them, the DC current generated by the rectifier circuit is controlled by the charging control module. The output of the mid - point of the half - bridge of the positive - polarity Marx circuit is connected to one end of the flyback transformer, and the other end of the flyback transformer is connected to the AC rectifier circuit. The positive - polarity Marx circuit module is composed of multiple cascaded units, and each unit includes a unidirectional diode, an energy - storage capacitor, an upper - bridge - arm switch, and a lower - bridge - arm switch. Among them, the charging switch (i.e., the lower - bridge - arm switch) is removed in the last - stage Marx module to avoid reverse - current interference. The input AC power supply is rectified by the rectifier circuit and then charges the positive - polarity Marx module through the charging control module. The positive - polarity Marx circuit is connected to the flyback transformer, and finally, high - voltage DC is output through the rectifier circuit. For details, see Figure 1 as shown.

[0006] The working principle of the high-voltage DC power supply device of the present invention is as follows:

[0007] The input AC power supply is rectified by the AC rectification circuit to obtain a DC voltage. The DC power is controlled by the charging switch for its charging mode, and the parallel charging and series discharging mode is used to charge the DC energy storage capacitor of the positive-polarity Marx circuit; after being modulated by the multi-stage Marx circuit, it outputs a voltage multiple times that of the DC voltage obtained after the AC rectification circuit, and then obtains another voltage boost through the flyback transformer, and obtains a high-voltage DC power supply output with a constant periodic current;

[0008] At the same time, when the positive-polarity Marx circuit is charged again, the magnetic energy stored in the flyback transformer discharges to the flyback rectification circuit. Due to the charging and discharging isolation characteristics of the Marx circuit, the MOS tube of the flyback circuit can be removed, so that it has no voltage stress limitation.

[0009] The present invention adopts an improved circuit design, based on the positive-polarity Marx topology structure, and its operation mode completes energy transfer through parallel charging and series discharging. On this basis, combined with the flyback transformer, its function is similar to that of the flyback circuit in the traditional switching power supply. However, due to the different freewheeling characteristics of the positive-polarity Marx circuit, in order to avoid the reverse feedback of energy in the flyback circuit, the traditional structure is optimized in the design, and the last-stage charging switch is cancelled, effectively solving the problem of reverse energy feedback.

[0010] The above technology is applied to the high-voltage DC power supply, which can significantly improve the voltage level, charging efficiency and speed. Therefore, the present invention has the unique advantages of high voltage, high frequency operation and fast charging.

[0011] The beneficial effects of the present invention are:

[0012] 1. It has a larger voltage transformation ratio and can effectively reduce the number of stages of the Marx circuit to save costs.

[0013] 2. It has lower restriction on the output current than an ordinary flyback transformer.

[0014] 3. By adjusting the transformation ratios of the positive-polarity Marx circuit and the flyback transformer, the charging voltage and the current value with a constant output period can be greatly improved.

[0015] The high-voltage DC power supply device of the present invention can be used in medium and small power high-frequency high-voltage DC output scenarios. Brief Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the positive-polarity single-bridge-arm Marx circuit and the flyback high-voltage DC power supply device of the present invention.

[0017] Figure 2 It is the circuit simulation of the present invention.

[0018] Figure 3It is the result of circuit simulation.

[0019] Reference numerals in the figure: 1 is the input AC power supply, 2 is the AC rectification circuit, 3 is the charging control switch, 4 is the positive-polarity Marx module, 5 is the unidirectional diode, 6 is the DC energy storage capacitor, 7 is the upper-bridge-arm switch, 8 is the lower-bridge-arm switch, 9 is the last-stage single-polarity Marx module, 10 is the flyback transformer, and 11 is the flyback rectification circuit. Specific implementation mode

[0020] In order to make the measures, creative features, achieved purposes and effects of the technical implementation of the present invention easy to understand, the present invention will be further described below with reference to specific illustrations.

[0021] Figure 1 The structure of a high-voltage DC power supply device based on a positive-polarity single-bridge-arm Marx circuit and a flyback transformer in the present invention is shown. The device consists of the following parts: input AC power supply 1, AC rectification unit 2, charging control switch 3, positive-polarity Marx module 4 (including unidirectional diode 5, DC energy storage capacitor 6, upper-bridge-arm switch 7 and lower-bridge-arm switch 8), last-stage positive-polarity Marx module 9, flyback transformer 10 and flyback rectification circuit 11. The AC power supply 1 is connected to the rectification unit 2, and the rectified direct current provides energy for multiple positive-polarity Marx modules in sequence through the charging control switch 3, and finally is connected to the primary coil of the flyback transformer 10. The secondary coil of the flyback transformer is connected to the flyback rectification circuit 11 to output high-voltage DC. During the operation of the system, the input alternating current is converted into direct current by the rectification unit 2 and enters the Marx module through the charging control switch 3. The unidirectional diode 5 and the lower-bridge-arm switch 8 realize the parallel charging of the energy storage capacitor 6. Then, through the upper-bridge-arm switch 7, the energy storage capacitor 6 transfers the electric energy to the flyback transformer 10 in series, so as to realize further voltage boost. During this period, the magnetic energy of the flyback transformer is also converted into a stable high-voltage DC output through the rectification circuit 11.

[0022] As Figure 2 the circuit is simulated, the 100V DC is boosted by the positive-polarity single-bridge-arm Marx circuit and the flyback transformer to obtain as Figure 3 the shown result.

[0023] The core design of the present invention is to use the positive-polarity Marx module to achieve primary voltage boost, complete secondary voltage boost through the flyback transformer, and at the same time rely on the flyback circuit to achieve current limiting and the periodic constancy of the output current. This combination not only improves the voltage gain and operation efficiency of the device, but also simplifies the overall structure, demonstrating an excellent design concept and practical value.

[0024] The above description has set forth the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, various changes and improvements will occur to the present invention, and all such changes and improvements fall within the scope of the present invention as claimed.

Claims

1. A high voltage DC power supply device based on a unipolar Marx circuit and a flyback transformer, characterized in that: The structure includes: Input AC power supply, rectifier circuit, charging control module, unipolar Marx circuit module, flyback transformer and flyback rectifier output module; wherein the DC current generated by the rectifier circuit is controlled by the charging control module; the midpoint output of the unipolar Marx circuit half bridge is connected to one end of the flyback transformer, and the other end of the flyback transformer is connected to the AC rectifier circuit; the unipolar Marx circuit module is composed of multiple cascade units, each unit includes a unidirectional diode, a storage capacitor, an upper bridge arm switch, and a lower bridge arm switch; wherein the charging switch is removed in the last-stage Marx module to avoid reverse current interference; the input AC power supply is rectified by the rectifier circuit and then charged by the charging control module for the unipolar Marx module, and finally high-voltage DC is output through the rectifier circuit.

2. The high voltage DC power supply device according to claim 1, characterized in that: The workflow is as follows: The input AC power is converted into a DC voltage after passing through the AC rectifier circuit. The charging mode of the DC power is controlled by the charging switch, and the DC energy storage capacitor of the unipolar Marx circuit is charged in the parallel charging and series discharging mode. After being modulated by the multi-stage Marx circuit, the output is multiple times that of the AC rectifier circuit to obtain a DC voltage, which is boosted again by the flyback transformer, and a high-voltage DC power supply output with a periodic current constant current is obtained. At the same time, when the unipolar Marx circuit is charged again, the magnetic energy stored in the flyback transformer is discharged to the flyback rectifier circuit.

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