Low-ripple high-voltage direct-current power supply

Abstract

The low-ripple high-voltage direct-current power supply comprises a plurality of boosting modules and a control unit, the boosting modules are arranged in parallel, one end of each boosting module is connected with an input end of alternating-current input, and the other end of each boosting module is connected with an output end in series; the boosting module comprises a rectifying and filtering unit, a power inversion rectifying unit and a high-voltage direct-current filtering unit which are connected in sequence; a plurality of boosting modules are arranged, each boosting module comprises a rectifying and filtering unit, a power inversion rectifying unit and a high-voltage direct-current filtering unit, each phase of series resonant converter works under the same switching frequency in cooperation with a control module, and phase differences exist between driving signals of switching tubes; and when the outputs of the N-phase series resonant converter are connected in series, the phase difference of the driving signals of the switching tubes of each phase is pi / N, so that the output after synthesis boosting, phase interleaving filtering and optimized rectification filtering is realized, the fluctuation frequency of the output voltage and current is increased, and the noise and the total output ripple can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of DC power supplies, and more particularly to a low-ripple high-voltage DC power supply. Background Technology

[0002] Currently, with the continuous development of deep space exploration technology, the exploration distance is constantly expanding, the measurement accuracy is steadily improving, and the data transmission rate is significantly increasing, making the promotion of key technologies for high-power continuous wave transmitters a trend.

[0003] In future deep space exploration missions, the output power of continuous wave transmitters will reach tens to hundreds of kilowatts. High-voltage direct current (HVDC) power supplies, as key power sources, primarily provide stable voltage and current to components such as the cathode, filament, magnetic field coil, and titanium pump. The magnitude of the output ripple directly affects the transmitter's energy conversion efficiency and the phase stability of the output signal. Therefore, researching efficient ripple control technology for HVDC power supplies is essential for ensuring the reliable operation of deep space exploration systems.

[0004] Traditional methods for reducing ripple voltage in high-voltage DC power supplies include increasing the filter capacitor in the power inverter unit and raising the switching frequency. However, there are limits to the increase in switching frequency; excessively high switching frequencies lead to increased switching losses, resulting in increased weight and size of the heatsink. Similarly, increasing the filter capacitor also increases the size and reduces the dynamic response speed. Summary of the Invention

[0005] The purpose of this invention is to provide a low-ripple high-voltage DC power supply that can reduce the output ripple voltage of the high-voltage DC power supply and improve the working efficiency and output signal quality of the high-power continuous wave transmitter.

[0006] The technical solution adopted in this invention is as follows:

[0007] A low-ripple high-voltage DC power supply includes multiple boost modules and a control unit. The multiple boost modules are arranged in parallel, with one end connected to the input terminal of the AC input and the other end connected in series with the output terminal. Each boost module includes a rectifier and filter unit, a power inverter and rectifier unit, and a high-voltage DC filter unit connected in sequence.

[0008] The rectifier and filter unit consists of an EMI filter, an uncontrolled rectifier bridge, a soft-start relay, a filter inductor, and an energy storage capacitor. One end of the EMI filter is connected to the input terminal of the AC input, and the other end is connected to the DC input terminal in sequence through the uncontrolled rectifier bridge, the soft-start relay, the filter inductor, and the energy storage capacitor.

[0009] The power inverter and rectifier unit consists of a DC / AC power inverter circuit, a high-frequency boost circuit, and a high-frequency rectifier circuit. The input terminal of the DC / AC power inverter circuit is connected to the DC input terminal, and the output terminal of the DC / AC power inverter circuit is connected to the high-frequency boost circuit and the high-frequency rectifier circuit in sequence, and then connected to the high-voltage output terminal.

[0010] The high-voltage DC filter device consists of a common-mode inductor, a common-mode capacitor, a differential-mode inductor, a differential-mode capacitor, a filter capacitor, a high-precision resistor divider, and a power dissipation circuit. The common-mode inductor is connected in parallel with the common-mode capacitor, the differential-mode inductor, the differential-mode capacitor, the filter capacitor, and the high-voltage resistor divider, and then connected in parallel with the power dissipation circuit.

[0011] The control module employs a phase-shift control circuit based on a logic control chip, specifically including a drive delay and drive pulse width setting circuit, a drive signal power amplification circuit, and an optical fiber transmitter. The output terminal of the drive delay and drive pulse width setting circuit is connected to the optical fiber transmitter through the drive signal power amplification circuit. The output signal of the optical fiber transmitter serves as a PWM drive signal, driving the switching transistors of the high-frequency rectifier circuit in the power inverter rectifier unit. By adjusting the phase difference and frequency of the PWM drive signal, the fluctuation frequency of the output voltage is increased, and the output ripple is reduced.

[0012] The EMI filter specifically comprises: capacitors C1 and C2 connected between the positive and negative terminals of the power supply; inductor L connected in series on the power line; inductor L employing a common-mode choke; capacitors C1 and C2 providing a low-impedance path for differential-mode noise, bypassing it; and the series inductor suppressing high-frequency current variations. Capacitors C3 and C4 direct noise to ground; and the common-mode choke of inductor L, through magnetic flux superposition, presents a high-mode configuration for common-mode signals.

[0013] The filter energy storage unit consists of an aluminum electrolytic capacitor and a polypropylene film capacitor connected in parallel. The aluminum electrolytic capacitor is responsible for energy transmission and storage, while the polypropylene film capacitor is responsible for absorbing the harmonic high-frequency components of the input grid voltage and the voltage spikes on the DC bus.

[0014] The DC / AC power inverter circuit adopts an H-bridge LC series resonant circuit. The H-bridge series resonant circuit and the high-voltage transformer in the subsequent stage together form a soft-switching conversion topology, which reduces switching noise and suppresses ripple.

[0015] The energy discharge circuit includes an energy discharge resistor and an energy discharge relay, and the energy discharge relay is controlled by the energy discharge control terminal of the control module.

[0016] The energy dissipation circuit has a two-way structure. Specifically, the first energy dissipation relay and the first energy dissipation resistor are connected in series to form an energy dissipation loop. The energy dissipation control circuit controls the on and off of the energy dissipation relay. The energy dissipation capacitor C1 and the energy dissipation resistor R1 are connected in parallel and then connected in parallel with the first energy dissipation control circuit. The energy dissipation capacitor C2 and the energy dissipation resistor R2 are connected in parallel with the second energy dissipation control circuit. This circuit can absorb the surge signal generated at the moment the relay is turned on and off.

[0017] The high-frequency rectifier circuit consists of multiple high-voltage rectifier diodes connected in series, and adopts a static and dynamic voltage equalization design: each diode is connected in parallel with a voltage equalization resistor, and in series with a current limiting protection resistor.

[0018] The rectifier diode is selected as a soft recovery diode. While maintaining a short reverse recovery time, the softness of the recovery process is optimized so that the reverse recovery current decreases smoothly, avoiding voltage oscillations and spike pulses caused by sudden current changes.

[0019] The logic control chip used is CD4098.

[0020] This invention employs multiple boost modules, each including a rectifier and filter unit, a power inverter rectifier unit, and a high-voltage DC filter unit. Combined with a control module, these modules ensure that each phase of the series resonant converter operates at the same switching frequency. The drive signals of the switching transistors have a phase difference, resulting in a π / N phase difference between the drive signals of each phase's switching transistors when the N-phase series resonant converter outputs in series. This achieves synthesized boost, phase-interleaved filtering, and optimized rectification and filtering before outputting the voltage. This not only increases the fluctuation frequency of the output voltage and current but also effectively reduces noise and overall output ripple. This invention effectively reduces high-voltage DC power supply ripple, which is of great significance for improving transmitter efficiency, signal quality, and ensuring long-term reliable operation of equipment. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram illustrating the working principle of the present invention;

[0023] Figure 2 This is a diagram of the two-phase series interleaved circuit described in this invention;

[0024] Figure 3 This is a schematic diagram of the rectifier filter unit of the present invention;

[0025] Figure 4 The circuit diagram of the EMI filter described in this invention is shown below.

[0026] Figure 5 The schematic diagram of the high-voltage rectifier bridge circuit is shown below.

[0027] Figure 6 This is a schematic diagram of the phase-shifting control circuit described in this invention;

[0028] Figure 7 This is a schematic diagram of waveforms with different interleaved phase numbers as described in this invention;

[0029] Figure 8 A schematic diagram showing the experimental comparison described in this invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] like Figure 1 , 2 As shown in Figure 3, this invention includes multiple boost modules and a control unit. The multiple boost modules are connected in parallel, with one end connected to the input terminal of the AC input and the other end connected in series with the output terminal. Each boost module includes a rectifier-filter unit, a power inverter-rectifier unit, and a high-voltage DC filter unit connected in sequence. This low-ripple high-voltage DC power supply generates high-voltage output by multiple boost modules connected in series and interleaved. Each boost module consists of a rectifier-filter unit, a power inverter-rectifier unit, and a high-voltage DC filter unit, as shown in Figure 3. Figure 1 As shown.

[0032] The magnitude of ripple is directly related to the step-up ratio of the power supply; under the same operating conditions, the higher the ratio, the greater the ripple. Based on this consideration, this low-ripple high-voltage DC power supply adopts a mode of multiple inverter step-up modules connected in series. Each step-up module uses a low-ratio transformer for primary voltage boosting, and the output stage of each inverter step-up module is connected in series for secondary voltage boosting, ultimately forming a high-voltage output.

[0033] The series interleaving method of the boost module output voltage is as follows: Figure 2As shown, taking a two-phase interleaved configuration as an example, phases A and B in the diagram are equivalent circuits of a single boost module. The output capacitor Cf1 of phase A is connected in series with the output capacitor Cf2 of phase B. The control module independently controls the PWM drive signal of each phase boost module, adjusting the frequency and phase of the PWM drive signals of the switching transistors of phase A and phase B boost units. The control module ensures that each phase series resonant converter operates at the same switching frequency, with a certain phase difference between the drive signals of the switching transistors. When the N-phase series resonant converter outputs are connected in series, the phase difference of the drive signals of each phase switching transistor is π / N, which increases the fluctuation frequency of the output voltage and current, effectively reducing noise and the total output ripple.

[0034] The rectifier and filter unit consists of an EMI filter, an uncontrolled rectifier bridge, a soft-start relay, a filter inductor, and an energy storage capacitor. One end of the EMI filter is connected to the AC input terminal, and the other end is connected to the DC input terminal sequentially through the uncontrolled rectifier bridge, the soft-start relay, the filter inductor, and the energy storage capacitor. Figure 3 As shown.

[0035] EMI filters use, for example Figure 4 In the circuit shown, capacitors C1 and C2 are connected across the positive and negative terminals of the power supply, and inductor L is connected in series on the power line. Inductor L uses a common-mode choke. Capacitors C1 and C2 provide a low-impedance path for differential-mode noise, bypassing it, while the series inductor suppresses high-frequency current variations. Capacitors C3 and C4 conduct noise to ground. The common-mode choke of inductor L presents a high-frequency configuration for common-mode signals through magnetic flux superposition. This circuit addresses the suppression requirements of both differential-mode and common-mode noise.

[0036] Adding a soft-start circuit (i.e., a soft-start resistor connected in parallel with a DC relay) between the uncontrolled rectifier bridge and the PFC inductor can reduce transient surge impact.

[0037] The filter energy storage unit consists of an aluminum electrolytic capacitor and a polypropylene film capacitor connected in parallel. The aluminum electrolytic capacitor is responsible for energy transmission and storage, while the polypropylene film capacitor is responsible for absorbing the harmonic high-frequency components of the input grid voltage and the voltage spikes on the DC bus.

[0038] The power inverter and rectifier unit consists of a DC / AC power inverter circuit, a high-frequency boost circuit, and a high-frequency rectifier circuit. The input terminal of the DC / AC power inverter circuit is connected to the DC input terminal, and the output terminal of the DC / AC power inverter circuit is connected to the high-frequency boost circuit, the high-frequency rectifier circuit, and then to the high-voltage output terminal. The DC / AC power inverter circuit adopts an H-bridge LC series resonant circuit. The H-bridge series resonant circuit and the subsequent high-voltage transformer together form a soft-switching conversion topology, which reduces switching noise and suppresses ripple.

[0039] The high-frequency rectifier circuit consists of multiple high-voltage rectifier diodes connected in series, and adopts a static and dynamic voltage equalization design: each diode is connected in parallel with a voltage equalization resistor, and in series with a current-limiting protection resistor. The current-limiting protection resistor has two functions: first, to limit the recovery current of the rectifier diode and improve the dynamic voltage equalization state of the high-voltage rectifier diode; second, to limit the current of the rectifier diode when the load has reverse voltage, thereby protecting the diode and suppressing spike pulses.

[0040] The rectifier diodes used are soft-recovery diodes. While maintaining a short reverse recovery time, the softness of the recovery process is optimized, resulting in a smooth decrease in reverse recovery current and avoiding voltage oscillations and spikes caused by sudden current changes. This approach not only meets the requirements for device withstand voltage and current carrying capacity but also suppresses spikes and reduces output voltage ripple.

[0041] like Figure 3 As shown, the inverter unit adopts an H-bridge LC series resonant circuit. The H-bridge series resonant circuit and the high-voltage transformer in the subsequent stage together form a soft-switching conversion topology, which reduces switching noise and suppresses ripple.

[0042] High-power high-frequency transformers use microcrystalline materials with high saturation magnetic induction intensity, high permeability, and low coercivity as the transformer core. The secondary winding of the coil adopts a split multi-segment winding series connection to achieve low leakage inductance and low temperature rise of the high-frequency transformer, reduce the transformer distributed parameters, and help suppress high-frequency noise in the circuit.

[0043] The high-voltage DC filter consists of a common-mode inductor, a common-mode capacitor, a differential-mode inductor, a differential-mode capacitor, a filter capacitor, a high-precision resistor divider, and a discharge circuit. The common-mode inductor is connected in parallel with the common-mode capacitor, differential-mode inductor, differential-mode capacitor, filter capacitor, and high-voltage voltage divider, and then connected in parallel with the discharge circuit. The common-mode inductor, common-mode capacitor, differential-mode inductor, and differential-mode capacitor filter out high-frequency noise generated by the switching power supply, reducing output noise and improving the accuracy of the DC high voltage. The current-limiting inductor is used to suppress short-circuit current in the main circuit, reducing damage to the system. The high-precision resistor divider realizes the output voltage sampling function. The discharge resistor and discharge relay realize the residual energy discharge function of the main circuit voltage.

[0044] The energy discharge circuit includes an energy discharge resistor and an energy discharge relay, and the energy discharge relay is controlled by the energy discharge control terminal of the control module.

[0045] The energy dissipation circuit has a two-way structure. Specifically, the first energy dissipation relay and the first energy dissipation resistor are connected in series to form an energy dissipation loop. The energy dissipation control circuit controls the on and off of the energy dissipation relay. The energy dissipation capacitor C1 and the energy dissipation resistor R1 are connected in parallel and then connected in parallel with the first energy dissipation control circuit. The energy dissipation capacitor C2 and the energy dissipation resistor R2 are connected in parallel with the second energy dissipation control circuit. This circuit can absorb the surge signal generated at the moment the relay is turned on and off.

[0046] The energy dissipation circuit design employs a relay with a dissipation resistor. Diodes D1 and D2 are connected in reverse parallel to the relay control coil. An absorption buffer circuit is added to the transistor controlling the relay's on / off state to suppress surge signals generated during relay switching. When the relay is closed, the energy stored in the capacitor is dissipated through the dissipation resistor. Furthermore, by connecting a common-mode inductor in series within the relay control circuit, common-mode interference is significantly reduced.

[0047] A high-precision resistance divider is selected as the sampling resistor. The high-voltage arm and low-voltage arm of the resistance divider use resistors of the same material and type, which have the same temperature coefficient. Through the isothermal body of the divider, the resistance is minimally affected by temperature, reducing drift caused by temperature fluctuations, which helps to improve detection accuracy and thus reduce the ripple of the high-voltage power supply.

[0048] The control module employs a phase-shift control circuit based on a logic control chip. Specifically, it includes a drive delay and drive pulse width setting circuit, a drive signal power amplification circuit, and an optical fiber transmitter. The output of the drive delay and drive pulse width setting circuit is connected to the optical fiber transmitter via the drive signal power amplification circuit. The output signal of the optical fiber transmitter serves as a PWM drive signal, driving the switching transistors of the high-frequency rectifier circuit in the power inverter rectifier unit. By adjusting the phase difference and frequency of the PWM drive signal, the fluctuation frequency of the output voltage is increased, and the output ripple is reduced. The logic control chip used is the CD4098.

[0049] The charging module adopts a series-interleaved charging mode. The control module ensures that each phase of the series resonant converter operates at the same switching frequency, with a phase difference between the drive signals of the switching transistors. When the N-phase series resonant converter outputs are connected in series, the phase difference between the drive signals of each phase switching transistor is π / N, which increases the fluctuation frequency of the output voltage and current, effectively reducing noise and total output ripple. The specific implementation scheme of the series-interleaved charging mode is as follows: a phase-shifting control circuit based on a logic control chip is used, such as... Figure 5 As shown.

[0050] This circuit includes a drive delay and drive pulse width setting circuit, a drive signal power amplification circuit, an optical fiber transmitter, etc. Figure 6As shown. First, by configuring the peripheral device parameters C1~C4 and R1~R4 of the logic control chip CD4098, the drive signal is expanded into multiple drive signals with adjustable delay time and pulse width. Then, the drive signal is amplified. Finally, the drive signal is transmitted to the corresponding low-voltage power supply module through an optical fiber transmitter to achieve the purpose of charging phase reversal control. Taking an N-phase series resonant converter with interleaved series connection as an example, the phase difference between the drive signals of each pair of adjacent phase switching transistors is 180° / N. We assume that the circuit parameters of each phase have no process error, then the output current of each phase will become I0 / N. We assume that the excitation voltage of each phase resonant converter is very large, and that the frequency of the switching transistor is close to the resonant frequency when it is working. Then, we equate the primary current of the transformer to a sine wave, and thus we can derive the expression for the total output current as:

[0051]

[0052] Based on the output voltage expression, the output current waveform of each phase and the total output current waveform within one operating cycle can be plotted, and then the output voltage ripple magnitude can be calculated. For example... Figure 7 The figure shows the output current waveform of each phase and the total output current waveform in one working cycle, taking two phases as an example. According to the figure, the output voltage ripple is reduced due to the interleaved connection.

[0053] Assuming the operating frequency of the resonant converter is infinitely close to the resonant frequency, and ignoring the effect of dead time, the circuit operates in a critical continuous state. Through specific numerical quantization, the variation law of the current ripple on the output filter capacitor as the number of phases increases is obtained as follows:

[0054] ΔI c =I Dmax -I Dmin ····················· (2)

[0055]

[0056] Where ΔI c The maximum ripple value, ΔI c % represents the ripple rate, I Dmax I Dmin i represents the output current of the rectifier network, respectively. D The maximum and minimum values ​​of the output load currents I0 and I. Dmax I Dmin The relationship between them is a formula:

[0057]

[0058] When there is only one item, I Dmax=I mi , where i represents the number of phases. Dmin =0, maximum ripple value ΔI c =I mi At this time, I0 and I mi The relationship formula is:

[0059]

[0060] The voltage ripple coefficient ΔI can be calculated. c % = 157%.

[0061] As the number of phases increases, the maximum ripple value ΔI can be determined according to the formula. c Output current and peak I per phase mi The relationship between these three quantities is shown in the table below, which illustrates the calculated ripple rate ΔI as the number of phases increases. c %size:

[0062] Table 1. Ripple rate ΔI calculated when the number of phases increases. c %size

[0063]

[0064]

[0065] Ideally, when the number of phases changes from one to two, the output voltage ripple is reduced to about 1 / 5 of the original value; when it changes to three phases, the output voltage ripple is reduced to about 1 / 10 of the original value; and when it changes to six phases, the output voltage ripple is reduced to about 1 / 47 of the original value.

[0066] The following uses specific experimental data to verify the effect:

[0067] Taking a 30kW / 30kV / 1A low-ripple high-voltage power supply as an example, the ripple of the high-voltage DC power supply was tested. The test scenario is as follows:

[0068] With a fixed load of 30kΩ, the waveforms on the oscilloscope are the voltage at terminals Q1 and Q4, the resonant current, the output voltage, the single-phase topology being tested, and the three-phase output voltage of 30kV.

[0069] At a frequency of 10kHz, such as Figure 8 a) The three phases are connected in series and interleaved, and the output voltage ripple is 300V.

[0070] At a frequency of 20kHz, such as Figure 8 c) The three phases are connected in series and interleaved, and the output voltage ripple is 150V.

[0071] At a frequency of 30kHz, such as Figure 8 e) The three phases are connected in series and interleaved, and the output voltage ripple is 130V.

[0072] Observe the changes in high-frequency ripple as the frequency is changed. It can be seen that the high-frequency ripple gradually decreases as the frequency increases.

[0073] Table 2. Output ripple values ​​for a three-phase load of 30kΩ, with frequencies of 10kHz, 20kHz, and 30kHz, and with or without interleaving.

[0074] Current curve frequency Waveform diagram Ripple size 1A <![CDATA[Voltages at Q1 and Q4, resonant current, output voltage]]> 10kHz a) 300V 1A <![CDATA[Voltages at Q1 and Q4, resonant current, output voltage]]> 20kHz c) 150V 1A <![CDATA[Voltages at Q1 and Q4, resonant current, output voltage]]> 30kHz e) 130V

[0075] It is evident that this solution can significantly reduce the output ripple of a high-voltage DC power supply.

[0076] Based on the above analysis, the present invention employs techniques such as synthetic boost, phase interleaved filtering, and optimized rectifier filter circuits to effectively reduce high-voltage DC power supply ripple, which is of great significance for improving transmitter efficiency, signal quality, and ensuring long-term reliable operation of equipment.

[0077] In the component selection stage, this invention is based on system parameters such as input power, output power, and output voltage; and the capacitance and inductance values ​​of the input filter network are calculated to meet ripple requirements. The circuit topology adopts a full-bridge resonant soft architecture, the resonant mode uses LC series resonance, and the soft-switching technology is implemented using zero-current switching (ZCS) across the entire load range.

[0078] Meanwhile, the high-voltage rectification section of the inverter boost unit adopts a high-voltage silicon stack full-bridge structure and is integrated with the boost transformer. Based on specific application scenarios, the output filter unit uses a passive filtering mode. The entire filter is based on a "single-stage filtering" architecture, which can be flexibly expanded into a multi-stage cascaded form according to actual application requirements.

[0079] This invention accelerates electrons to the speed of light through a high-voltage electric field using a klystron, forming a high-density electron beam. Ripple directly affects the periodic fluctuations of the cathode voltage, thus affecting the speed and density of the electron beam. Reducing ripple improves the uniformity of the electron beam, making the output power more stable. The output ripple of a high-voltage DC power supply mainly includes low-frequency input ripple, high-frequency switching ripple, and common-mode ripple caused by parasitic parameters. In high-power continuous wave transmitters, ripple control of the high-voltage DC power supply is one of the core requirements of system design. Reducing ripple is of great significance for improving transmitter efficiency and signal quality, and is also a key measure to ensure long-term reliable operation of the equipment and extend the life of core components.

[0080] This invention, through experimental research, reveals that reducing ripple is a crucial way to improve output power stability. High-voltage DC power supply ripple generates spectral sideband spurious signals in the output microwave signal through modulation effects. Suppressing ripple helps improve the signal-to-noise ratio and reduce phase noise. Therefore, reducing ripple improves signal spectral purity and phase stability. Ripple components superimposed on the high-voltage DC power supply cause voltage fluctuations, leading to additional thermal stress and electric field distortion in the klystron, and inducing resonance, thus affecting the klystron's lifespan and reliability. Controlling the high-voltage DC power supply ripple helps reduce system heat dissipation, extend klystron lifespan, and improve transmitter reliability; therefore, reducing ripple is of great significance for improving transmitter lifespan and reliability.

[0081] In the description of this invention, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0082] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0083] Note that the above description is merely a preferred embodiment and application of the technical principles of the present invention. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include many other effective embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A low-ripple high-voltage DC power supply, characterized by: The application relates to a voltage-boosting module and a control unit, wherein the voltage-boosting module is connected with an AC input at one end and connected with an output end in series at the other end; the voltage-boosting module comprises a rectifier filter unit, a power inverter rectifier unit and a high-voltage DC filter unit connected in sequence. The rectifier filter unit is composed of an EMI filter, an uncontrolled rectifier bridge, a soft start relay, a filter inductor and an energy storage capacitor; one end of the EMI filter is connected with the input end of the AC input, and the other end is connected with the DC input end through the uncontrolled rectifier bridge, the soft start relay, the filter inductor and the energy storage capacitor in sequence. The power inverter rectifier unit is composed of a DC / AC power inverter circuit, a high-frequency boost circuit and a high-frequency rectifier circuit; the input end of the DC / AC power inverter circuit is connected with the DC input end, and the output end of the DC / AC power inverter circuit is connected with the high-frequency boost circuit and the high-frequency rectifier circuit in sequence and then connected with the high-voltage output end. The high-voltage DC filter device is composed of a common-mode inductor, a common-mode capacitor, a differential-mode inductor, a differential-mode capacitor, a filter capacitor, a high-precision resistance voltage divider and a energy release circuit; the common-mode inductor is connected with the common-mode capacitor, the differential-mode inductor, the differential-mode capacitor, the filter capacitor and the high-voltage resistance voltage divider in parallel and then connected with the energy release circuit in parallel. The control module adopts a phase-shift control circuit based on a logic control chip and specifically comprises a driving delay and driving pulse width setting circuit, a driving signal power amplification circuit and a fiber-optic transmitter; the output end of the driving delay and driving pulse width setting circuit is connected with the fiber-optic transmitter through the driving signal power amplification circuit; the fiber-optic transmitter outputs a signal as a PWM driving signal to drive the switching tube of the high-frequency rectifier circuit in the power inverter rectifier unit; the phase difference and frequency of the PWM driving signal are adjusted to improve the fluctuation frequency of the output voltage and reduce the output ripple.

2. The low-ripple high-voltage DC power supply of claim 1, wherein: The EMI filter is specifically composed of capacitors C1 and C2 connected in cross between the positive and negative poles of a power supply, an inductor L connected in series on a power supply line, a common-mode choke used as the inductor L, and capacitors C1 and C2 providing a low-impedance channel for differential-mode noise, bypassing the differential-mode noise and using the series inductor to suppress high-frequency current changes; capacitors C3 and C4 guide noise to the ground, and the common-mode choke of the inductor L presents a high configuration to common-mode signals through magnetic flux superposition.

3. The low-ripple high-voltage DC power supply of claim 2, wherein: The filter energy storage unit is composed of an aluminum electrolytic capacitor and a polypropylene film capacitor connected in parallel; the aluminum electrolytic capacitor is responsible for electric energy transmission and storage, and the polypropylene film capacitor is responsible for absorbing the harmonic high-frequency components of the input network voltage and the voltage spikes on the DC bus.

4. The low-ripple high-voltage DC power supply of claim 1, wherein: The DC / AC power inverter circuit adopts an H full-bridge LC series resonant circuit; the H full-bridge series resonant circuit and a high-voltage transformer in the subsequent stage together form a soft-switching conversion topology, which can reduce switching noise and suppress ripples.

5. The low-ripple high-voltage DC power supply of claim 1, wherein: The energy release circuit comprises an energy release resistor and an energy release relay, and the energy release relay is controlled by the energy release control end of the control module.

6. The low-ripple high-voltage DC power supply of claim 5, wherein: The energy release circuit is a two-way structure, specifically, the first energy release relay and the first energy release relay are connected in series with the corresponding energy release resistor, forming an energy release loop, the energy release relay is controlled by the energy release control circuit to be turned on and off, the energy release capacitor C1 and the energy release R1 are connected in parallel and then connected in parallel with the first energy release control circuit, the energy release capacitor C2 and the energy release resistor R2 are connected in parallel with the second energy release control circuit, and the surge signal generated in the opening and closing moment of the absorption relay is absorbed.

7. The low-ripple high-voltage DC power supply of any of claims 1-6, wherein: The high-frequency rectification circuit is composed of a plurality of high-voltage rectifier tubes connected in series, and adopts static and dynamic voltage balancing design: each diode is connected in parallel with a voltage balancing resistor, and a current limiting protection resistor is connected in series.

8. The low-ripple high-voltage DC power supply of claim 7, wherein: The rectifier diode selects a soft recovery characteristic diode, which optimizes the softness of the recovery process while maintaining a short reverse recovery time, so that the reverse recovery current decreases gently, avoiding voltage oscillation and sharp pulse caused by current mutation.

9. A low-ripple high-voltage DC power supply as claimed in any of claims 8, characterized in that: The logic control chip adopts CD4098.

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