High-precision high-voltage charging power supply circuit

Abstract

The utility model discloses a high-precision high-voltage charging power supply circuit, which comprises a high-frequency transformer, a plurality of LC resonant circuits and a plurality of rectifying circuits, wherein each LC resonant circuit is loaded to the primary side of the high-frequency transformer through a winding; each rectifying circuit is loaded on the secondary side of the high-frequency transformer through a winding; each LC resonance circuit is connected to a direct current (DCV) power supply; and the output ends of the rectifying circuits are connected in series to form a high-voltage output end HV. The charging power supply circuit provided by the utility model can realize a high-precision charging power supply with low cost.

Description

Technical Field

[0001] This utility model relates to the field of pulse power electronics technology, and in particular to a high-precision high-voltage charging power supply circuit. Background Technology

[0002] Traditional DC power supplies provide a predetermined output voltage or current to a nearly fixed load. However, with the rapid development of pulsed power electronics, capacitor-charging power supplies (CCPS) have found widespread application. In pulsed power electronic systems, such as pulse modulators, electromagnetic railguns, radiotherapy, industrial irradiation, and flaw detection imaging, switching devices are used to discharge energy storage capacitors (or equivalent capacitors) in a very short time to form pulses, providing high instantaneous power. After the energy stored in the capacitors is released, they need to be recharged to a specific voltage using a capacitor-charging power supply. For example, a battery-powered pulsed capacitor-charging power supply with patent application number 202211157708.9 uses a two-stage pulsed capacitor-charging power supply structure composed of an interleaved parallel dual-boost converter and an LCC resonant converter. The front stage achieves stable voltage boost through voltage and current dual closed-loop control, improving response speed. The rear stage achieves full-range soft switching and constant current charging through critical discontinuous constant current control, improving charging speed, charging efficiency, and charging linearity.

[0003] The accuracy of the pulse discharge current mainly depends on the accuracy of the charging voltage control of the capacitor charging power supply. The voltage waveform on the energy storage capacitor connected to the output of the capacitor charging power supply is shown in the attached figure. Figure 1 As shown. After the charging process begins, the capacitor charging power supply charges the capacitor with a certain current, causing its voltage to rise. When the capacitor voltage reaches the preset value, charging stops, and the power supply enters the replenishment mode until the capacitor begins to discharge to the load, entering the discharge process.

[0004] Currently, the existing LC resonant charging power supply is a relatively traditional charging mode. It uses full-bridge rectification to form a bus inductance, and then uses the switching transistors on the full-bridge to alternately conduct, charging the load by resonating the inductor and capacitor. The accuracy of this type of charging power supply can only reach about 0.5%. With the continuous development and improvement of the technology of related equipment, the low charging accuracy of the charging power supply can no longer meet the requirements. Some equipment has raised the requirements for the precise control accuracy of the charging voltage of the capacitor charging power supply to better than 0.05%. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-precision high-voltage charging power supply circuit that can achieve high-precision charging power at low cost.

[0006] In order to achieve the above object, the technical scheme adopted by the present application is as follows: a high-precision high-voltage charging power supply circuit, comprising a high-frequency transformer, a plurality of LC resonance circuits and a plurality of rectifier circuits; wherein:

[0007] Each LC resonance circuit is loaded to the primary side of the high-frequency transformer through a winding; each rectifier circuit is loaded to the secondary side of the high-frequency transformer through a winding; each LC resonance circuit is connected to a DC power supply DCV; and the output ends of each rectifier circuit are connected in series to form a high-voltage output end HV.

[0008] Each LC resonance circuit comprises a bridge circuit composed of four MOS tubes, and two terminals are led out between each two MOS tubes of the bridge circuit, one of which is directly connected to one end of the winding, and the other end of the winding is connected to the other terminal through a capacitor C2 and an inductor L1.

[0009] Each rectifier circuit comprises a bridge rectifier composed of diodes, the input end of the bridge rectifier is connected to the corresponding winding, the positive and negative output ends of the bridge rectifier are connected to the negative and positive output ends of the adjacent bridge rectifier, so as to realize the series connection of the output ends of the bridge rectifiers; a capacitor C5 is arranged in parallel between the positive and negative output ends of each bridge rectifier; and a resistor R1 is arranged in parallel at both ends of the capacitor C5.

[0010] The rectifier circuit is at least 4-way.

[0011] The LC resonance circuit is at least two-way.

[0012] The charging power supply circuit further comprises a charging controller, when the LC resonance circuit is two-way, the charging controller controls the two-way LC resonance circuit to work simultaneously in the fast charging stage, and controls the two-way LC resonance circuit to work in the staggered parallel mode in the buffer charging stage.

[0013] The charging controller is connected with a charging voltage, and the charging controller controls the switching between the fast charging stage and the buffer charging stage according to the charging voltage.

[0014] The present application has the advantages that: the two-way LC resonance circuit and the single-way LC resonance circuit have the same circuit principle, but a small-power tube can be used to realize a large-power charging current output, so that the power supply cost can be effectively reduced; the high-precision charging power supply requirement is effectively realized on the basis of retaining the advantages of the traditional LC resonance charging power supply. The circuit is simple and reliable, has strong anti-interference ability, and has small size and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0015] The contents expressed by each drawing in the specification of the present application and the marks in the drawings are briefly described as follows:

[0016] Figure 1A schematic diagram of a conventional charging process in the prior art;

[0017] Figure 2 A high-precision high-voltage charging power supply circuit of the utility model;

[0018] Figure 3 A slow charging control timing diagram of the utility model;

[0019] Figure 4 A high-precision charging process schematic diagram of the utility model. DETAILED DESCRIPTION

[0020] The specific embodiments of the present application are further described in detail with reference to the accompanying drawings.

[0021] The high-voltage charging power supply circuit provided in the embodiment mainly improves the precision of the charging power supply circuit while reducing the cost, so that the circuit is more simple and reliable, and the cost is low. Figure 2 As shown in the figure.

[0022] As shown in the figure. Figure 2 A high-precision high-voltage charging power supply circuit, comprising a high-frequency transformer, a plurality of LC resonance circuits and a plurality of rectifier circuits; wherein:

[0023] Each LC resonance circuit is loaded on the primary side of the high-frequency transformer through a winding; each rectifier circuit is loaded on the secondary side of the high-frequency transformer through a winding; each LC resonance circuit is connected to a DC power supply DCV; and the output ends of each rectifier circuit are connected in series to form a high-voltage output end HV.

[0024] As shown in the figure. Figure 2 In order to achieve the dual requirements of control precision and low cost, the embodiment is provided with two LC resonance circuits and four rectifier circuits to realize the high-voltage charging power supply.

[0025] In the scheme, each LC resonance circuit comprises a bridge circuit composed of four MOS tubes, in the first LC resonance circuit, two terminals are led between every two MOS tubes of the bridge circuit, one of the two terminals is directly connected to one end of the winding, and the other end of the winding is connected to the other terminal through a capacitor C2 and an inductor L1. In the second LC resonance circuit, two terminals are led between every two MOS tubes of the bridge circuit, one of the two terminals is directly connected to one end of the winding, and the other end of the winding is connected to the other terminal through a capacitor C3 and an inductor L2. The two windings are independent windings and are loaded on the primary side of the high-frequency transformer.

[0026] Four secondary side windings are arranged on the secondary side of the high-frequency transformer, each of which is connected to a rectifier circuit. Each rectifier circuit comprises a bridge rectifier composed of diodes, the input of the bridge rectifier is connected to the corresponding winding, the positive and negative outputs of the bridge rectifier are connected to the negative and positive outputs of the adjacent bridge rectifier, so as to realize the series connection of the outputs of the bridge rectifiers; a capacitor C5 is arranged in parallel between the positive and negative outputs of each bridge rectifier; and a resistor R1 is arranged in parallel across the capacitor C5. The positive and negative outputs of the outputs of the two rectifier circuits at the two ends of the four rectifier circuits in series are taken out as the positive HV+ and negative HV- of the charging power supply, and a charging capacitor CLOAD is connected between HV+ and HV-.

[0027] When the charging control is performed, the charging controller is used for control, and the charging process can be controlled by controlling the conduction state of the MOS tube in the LC resonant circuit through the charging controller. The charging controller is connected with a charging voltage sensor, the charging voltage sensor is used for collecting the charging voltage, and the charging controller controls the switching between the fast charging stage and the buffer charging stage according to the charging voltage. As shown in Figure 4 , different charging stages are used when the charging voltage reaches different voltage values, and the collected charging voltage can be obtained by obtaining the voltage across the CLOAD through the voltage sensor. Therefore, the LC resonant circuit can be controlled by collecting the charging voltage, and the control scheme is as follows:

[0028] When the LC resonant circuit is two-way, the charging controller controls the two-way LC resonant circuit to work simultaneously in the fast charging stage, and controls the two-way LC resonant circuit to work in the staggered parallel mode in the buffer charging stage.

[0029] The embodiment provides a high-precision high-voltage charging power supply circuit (as shown in the accompanying Figure 2 ): two-way LC resonant circuits are used, two groups of the same and independent windings are loaded on the high-frequency transformer, the high-frequency transformer is coupled, and then a plurality of rectifier circuits are used for rectification to form a high-voltage constant current source for charging the required capacitor. The two-way LC resonant circuits work in the complete parallel mode in the fast charging stage of the capacitor, and work in the staggered parallel mode when the charging reaches the preset buffer charging control value. This means that the fast charging stage charging power supply works at twice the charging current, and the buffer charging works at one time the charging current, so that the charging power supply precision can be effectively improved. The charging control timing and the charging process are as shown in the accompanying Figures 3-4 , and the purpose of the high-precision high-voltage charging power supply is achieved.

[0030] The present application has the advantages that: the two-way LC resonant circuit has the same circuit principle as the single-way LC resonant circuit, but can realize the output of high-power charging current by using small-power tubes, so that the power supply cost can be effectively reduced; the high-precision charging power supply requirement is effectively realized on the basis of retaining the advantages of the traditional LC resonant charging power supply. The circuit is simple and reliable, has strong anti-interference ability, and the whole power supply has small size and low cost.

[0031] Obviously, the specific implementation of the present application is not limited by the above-mentioned manner, and various non-essential improvements made by adopting the method concept and technical scheme of the present application are within the protection scope of the present application.

Claims

1. A high-precision high-voltage charging power supply circuit, characterized by: The high-frequency transformer, the multi-path LC resonance circuit and the multi-path rectifier circuit are included. Each LC resonance circuit is loaded on the primary side of the high-frequency transformer through a winding, and each rectifier circuit is loaded on the secondary side of the high-frequency transformer through a winding.

2. A high-precision high-voltage charging power supply circuit according to claim 1, characterized in that: Each LC resonance circuit includes a bridge circuit composed of four MOS tubes, and two paths of terminals are led out between each two MOS tubes of the bridge circuit, one of which is directly connected to one end of the winding, and the other end of the winding is connected to the other path of terminals through a capacitor C2 and an inductor L1.

3. A high-precision high-voltage charging power supply circuit as claimed in claim 1, characterized in that: Each rectifier circuit includes a bridge rectifier composed of diodes, the input end of the bridge rectifier is connected to the corresponding winding, the positive and negative output ends of the bridge rectifier are connected to the positive and negative output ends of the adjacent bridge rectifier, so that the output ends of the bridge rectifiers are connected in series, and a capacitor C5 is arranged in parallel between the positive and negative output ends of each bridge rectifier, and a resistor R1 is arranged in parallel at both ends of the capacitor C5.

4. A high-precision high-voltage charging power supply circuit according to any one of claims 1 to 3, characterized in that: The rectifier circuit is at least four paths.

5. A high-precision high-voltage charging power supply circuit according to any one of claims 1 to 3, characterized in that: The LC resonance circuit is at least two paths.

6. A high-precision high-voltage charging power supply circuit according to any one of claims 1 to 3, characterized in that: The charging power supply circuit further includes a charging controller, when the LC resonance circuit is two paths, the charging controller controls the two LC resonance circuits to work simultaneously in the fast charging stage, and controls the two LC resonance circuits to work in the staggered parallel mode in the buffer charging stage.

7. A high-precision high-voltage charging power supply circuit as claimed in claim 6, characterized in that: The charging controller is connected with a charging voltage sensor, and the charging controller controls the switching of the fast charging stage and the buffer charging stage according to the charging voltage.

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