Low-ripple high-voltage power supply control system

Abstract

The utility model relates to a low-ripple high-voltage power supply control system, which comprises an input rectification unit, a plurality of power conversion units and an output unit which are sequentially arranged, and the plurality of power conversion units are mutually connected in parallel and are arranged between the input rectification unit and the output unit; the input rectifying unit is used for rectifying an input original power supply to obtain high-ripple direct current; the plurality of power conversion units are used for dividing the high-ripple direct current into a plurality of paths of direct current to reduce amplitude, and performing inversion, voltage regulation and rectification on the high-ripple direct current after amplitude reduction in sequence to obtain a plurality of paths of low-ripple direct current; and the output unit is used for superposing the multiple paths of low-ripple direct current so as to output low-ripple high-voltage direct current. According to the system, the high-ripple direct-current source obtained through rectification is divided into a plurality of branches to be processed respectively, then the obtained multiple paths of direct-current sources with small ripples are superposed and output, the obtained high-voltage direct-current ripples are effectively suppressed, and the quality of the high-voltage direct-current source is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high - voltage power supplies, and particularly to a low - ripple high - voltage power supply control system. Background Art

[0002] Ripple is a phenomenon caused by the voltage fluctuation of a DC stabilized power supply. Since a DC stabilized power supply is generally formed by rectifying and regulating an AC power supply, it is inevitable that there is some AC component in the DC stabilized quantity. This AC component superimposed on the DC stabilized quantity is called ripple.

[0003] In many electronic devices and industrial applications, the performance of high - voltage power supplies is crucial for the stability and reliability of the system. However, traditional high - voltage power supplies often have the problem of large ripple, which will have an adverse impact on the normal operation of the equipment, such as reducing measurement accuracy, interfering with signal transmission, shortening the service life of electronic components, etc.

[0004] Therefore, it is necessary to study a solution that can effectively suppress the ripple of high - voltage power supplies to improve the performance of high - voltage power supplies. Summary of the Utility Model

[0005] Based on the above description, the utility model provides a low - ripple high - voltage power supply control system to solve the problem of high ripple in high - voltage DC sources.

[0006] The technical solution of the utility model to solve the above - mentioned technical problems is as follows: A low - ripple high - voltage power supply control system includes an input rectification unit, a plurality of power conversion units, and an output unit arranged in sequence. The plurality of power conversion units are arranged in parallel between the input rectification unit and the output unit;

[0007] The input rectification unit is used to rectify the input original power supply to obtain high - ripple direct current;

[0008] The plurality of power conversion units are used to divide the high - ripple direct current into multiple paths of direct current to reduce the amplitude, and then sequentially invert, regulate the voltage, and rectify the reduced - amplitude high - ripple direct current to obtain multiple paths of low - ripple direct current;

[0009] The output unit is used to superimpose the multiple paths of low - ripple direct current to output low - ripple high - voltage direct current.

[0010] Compared with the existing technology, the technical solution of this application has the following beneficial technical effects: the present invention divides the high-ripple DC source obtained through rectification into multiple branches for separate processing, reducing the ripple amplitude by reducing the amplitude. The DC source in each branch is then subjected to inversion, rectification, voltage regulation, filtering, and other processing to obtain multiple DC sources with low ripple. The multiple DC sources are then superimposed and output to obtain a final high-voltage DC power with low ripple. Through the processing of the present invention, the ripple of the resulting high-voltage DC power is effectively suppressed, improving the quality of the high-voltage DC source.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, the input rectifier unit includes a first rectifier bridge and a first inductor, the AC input end of the first rectifier bridge is connected to an external power supply, the positive pole of the DC output end of the first rectifier bridge is connected in series with the first inductor, the end of the first inductor facing away from the first rectifier bridge serves as the positive output end of the input rectifier unit, and the negative pole of the DC output end of the first rectifier bridge serves as the negative output end of the input rectifier unit.

[0013] Furthermore, the power conversion unit includes an inverter module, an LLC resonant module and a rectifier voltage regulating circuit arranged in sequence;

[0014] The DC input end of the inverter module is connected to the output end of the input rectifier unit, and the AC output end of the inverter module is connected to the LLC resonant module, for inverting the reduced high ripple DC power into single-phase AC power;

[0015] The LLC resonant module is used to realize the soft opening of the inverter module and is also used to output the single-phase AC power after voltage regulation;

[0016] The input end of the rectifier and voltage regulator circuit is connected to the output end of the LLC resonant module, and the output end of the rectifier and voltage regulator circuit is connected to the output unit, which is used to rectify and filter the regulated single-phase AC power to output low-ripple DC power.

[0017] Furthermore, the power conversion unit further includes a peak absorption capacitor, one end of which is connected to the positive DC input terminal of the inverter module, and the other end of which is connected to the negative DC input terminal of the inverter module.

[0018] Furthermore, the control signal interval time t of the inverter modules in two adjacent power conversion units satisfies the following conditions:

[0019] t=T*D / n,

[0020] T is the period of the PWM signal, D is the duty cycle of the high level in the PWM signal, and n is the number of the power conversion units.

[0021] Further, the LLC resonance module includes a resonance capacitor, a transformer, and a resonance inductor. The resonance capacitor, the primary of the transformer, and the resonance inductor are sequentially connected in series at the AC output end of the inverter module to form a loop, and the secondary of the transformer is connected to the rectification and voltage regulation circuit.

[0022] Further, the rectification and voltage regulation circuit includes a first energy storage capacitor C3, a second energy storage capacitor C4, a third energy storage capacitor C5, a fourth energy storage capacitor C6, a fifth energy storage capacitor C7, a sixth energy storage capacitor C8, and first rectifier diodes D1 to eighth rectifier diodes D8. The rectification and voltage regulation circuit is connected to the secondary of the transformer T1;

[0023] The secondary winding of the transformer T1 has a center tap. The center tap of the secondary winding of the transformer is sequentially connected in series with the first rectifier diodes D1 to fourth rectifier diodes D4 and then connected to the DC output terminal HV+. The center tap of the secondary winding of the transformer is also sequentially connected in series with the fifth rectifier diodes D5 to eighth rectifier diodes D8 and then connected to the DC output terminal; the cathodes of the first rectifier diodes D1 to eighth rectifier diodes D8 all face the DC output terminal HV+, and the anodes of the first rectifier diodes D1 to eighth rectifier diodes D8 all face the center tap of the secondary winding of the transformer; the center tap of the secondary winding of the transformer is also sequentially connected in series with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 and then connected to the DC output terminal HV+; the common node of the second rectifier diode D2 and the third rectifier diode D3, the common node of the sixth rectifier diode D6 and the seventh rectifier diode D7, and the common node of the third energy storage capacitor C5 and the fourth energy storage capacitor C6 are connected;

[0024] One end of the secondary winding of the transformer is sequentially connected in series with the first energy storage capacitor C3 and the second energy storage capacitor C4 and then connected to the common node of the third rectifier diode D3 and the fourth rectifier diode D4, and the common node of the first energy storage capacitor C3 and the second energy storage capacitor C4 is connected to the common node of the first rectifier diode D1 and the second rectifier diode D2;

[0025] The other end of the secondary winding of the transformer is sequentially connected in series with the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 and then connected to the common node of the seventh rectifier diode D7 and the eighth rectifier diode D8, and the common node of the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 is connected to the common node of the fifth rectifier diode D5 and the sixth rectifier diode D6.

[0026] Further, the output unit includes a resistor R1, and the DC output terminals HV+ of all the rectification and voltage regulation circuits are connected in parallel to the resistor R1.

[0027] Further, it further includes a feedback circuit, which is used to detect the low-ripple direct current output by the rectification and voltage regulation circuit and / or the low-ripple high-voltage direct current output by the output unit.

[0028] Further, it further includes a control unit. The input end of the control unit is connected to the feedback circuit, and the output end of the control unit is connected to the control end of the inverter module, and is used to adjust the control signal of the inverter module according to the detection signal of the feedback circuit. Description of the Drawings

[0029] Figure 1 It is a block diagram of the structural composition of a low-ripple high-voltage power supply control system provided by an embodiment of the present invention;

[0030] Figure 2 It is the partial circuit principle of a low-ripple high-voltage power supply control system provided by an embodiment of the present invention Figure 1 ;

[0031] Figure 3 It is the partial circuit principle of a low-ripple high-voltage power supply control system provided by an embodiment of the present invention Figure 2 ;

[0032] Figure 4 It is a timing diagram of the control signals of each inverter module in the scenario of setting 6 power conversion units;

[0033] Figure 5 It is for Figure 4 The simulation diagram of the single-phase alternating current output by each inverter module under the shown control timing;

[0034] Figure 6 It is for Figure 3 The circuit direction diagram of the rectification and voltage regulation circuit when the transformer works in the negative half cycle in the embodiment;

[0035] Figure 7 It is for Figure 3 The circuit direction diagram of the rectification and voltage regulation circuit when the transformer works in the positive half cycle in the embodiment.

[0036] In the drawings, the list of components represented by each reference numeral is as follows:

[0037] UR1, the first rectifier bridge, L1, the first inductor, C1 / C2, spike absorption capacitors, Q1~Q8, power switch tubes, Cr1 / Cr2, resonant capacitors, Lr1 / Lr2, resonant inductors, T1, transformer, V1 / V2, single-phase alternating current, D1~D8, the first rectifier tube to the eighth rectifier tube, C3, the first energy storage capacitor, C4, the second energy storage capacitor, C5, the third energy storage capacitor, C6, the fourth energy storage capacitor, C7, the fifth energy storage capacitor, C8, the sixth energy storage capacitor, R1, resistor, HV+, direct current output terminal. Detailed implementation manners

[0038] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] It can be understood that spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, spatial relationship terms also include different orientations of the device during use and operation. For example, if the device in the drawing is flipped, the element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "beneath" can include both the upper and lower orientations. In addition, the device can also include other orientations (such as rotating 90 degrees or other orientations), and the spatial description terms used herein are correspondingly interpreted.

[0041] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection", if there is an electrical signal or data transfer between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0042] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" or "having" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0043] Figure 1 It is a block diagram of the structural composition of a low-ripple high-voltage power supply control system provided for an embodiment of the present utility model. As Figure 1As shown in the figure, an embodiment of the present utility model provides a low-ripple high-voltage power supply control system, which includes an input rectification unit, a plurality of power conversion units, and an output unit arranged in sequence. The plurality of power conversion units are connected in parallel with each other, and the plurality of power conversion units are arranged in parallel between the input rectification unit and the output unit;

[0044] The input rectification unit is used to rectify the input original power supply (such as three-phase alternating current) to obtain high-ripple direct current;

[0045] The plurality of power conversion units are used to reduce the amplitude of the high-ripple direct current, and the high-ripple direct current after amplitude reduction is successively subjected to inversion, voltage regulation, and rectification to obtain multiple paths of low-ripple direct current;

[0046] The output unit is used to superimpose multiple paths of the low-ripple direct current to output low-ripple high-voltage direct current.

[0047] It can be understood that for the low-ripple high-voltage power supply control system provided in this embodiment, the high-ripple DC source obtained by direct rectification is divided into multiple branches (power conversion units) for separate processing. Since the large DC current is shunted into multiple paths of small DC currents, the amplitude of the DC current in each branch is reduced, and the amplitude of the AC ripple in the DC is also suppressed. Then, the DC sources in each branch (power conversion unit) are respectively subjected to inversion, rectification, voltage regulation, filtering, etc. Multiple paths of DC sources with smaller ripple can be obtained, and then the multiple paths of DC sources are superimposed and output to obtain the final high-voltage DC with lower ripple. During the inversion process, the phase difference between the alternating currents generated by inversion in each branch can be made by controlling the difference in the conduction times between different branches, or the frequency of the single-phase alternating current generated by inversion in each branch can be flexibly adjusted, thereby further reducing the ripple. Through the rectification and voltage regulation processes, the DC voltage of the final output can also be adjusted to the desired voltage value to meet the requirements of the high-voltage DC source for multiple voltage levels. Through the processing of the present utility model, the ripple of the finally obtained high-voltage DC is effectively suppressed, and the quality of the high-voltage DC source is improved.

[0048] In one possible implementation manner, as Figure 2As shown, the input rectification unit includes a first rectifier bridge UR1 and a first inductor L1. The AC input terminals of the first rectifier bridge UR1 are connected to the externally input three-phase power supply. The positive pole of the DC output terminal of the first rectifier bridge UR1 is connected in series with the first inductor L1. One end of the first inductor L1 away from the first rectifier bridge UR1 serves as the positive output terminal of the input rectification unit, and the negative pole of the DC output terminal of the first rectifier bridge UR1 serves as the negative output terminal of the input rectification unit to output the highly-rippled direct current obtained from the primary rectification. The first inductor L1 plays a role in voltage regulation and filtering, making the highly-rippled direct current output by the input rectification unit more stable.

[0049] In one possible implementation, in combination with Figure 1 and Figure 2 as shown, the system is provided with a plurality of the power conversion units. Each power conversion unit serves as a branch to separately process the highly-rippled direct current with a slightly smaller amplitude divided from the highly-rippled direct current output by the input rectification unit. The specific number of the power conversion units is determined according to actual requirements. In principle, the more the number of the power conversion units, the less the ripple component in the finally obtained high-voltage direct current. For the sake of illustration, for example, Figure 2 shows a case with two power conversion units. Of course, more power conversion units can also be set in parallel, such as six, which will not be elaborated here.

[0050] Referring to Figure 2 and Figure 3 , taking any one of the power conversion units as an example, the power conversion unit includes an inverter module, an LLC resonant module, and a rectification and voltage regulation circuit arranged in sequence;

[0051] The DC input terminal of the inverter module is connected to the output terminal of the input rectification unit, and the AC output terminal of the inverter module is connected to the LLC resonant module, which is used to invert the reduced highly-rippled direct current into single-phase alternating current;

[0052] The LLC resonant module is used to realize the soft turn-on of the inverter module and is also used to output the single-phase alternating current after voltage regulation;

[0053] The input terminal of the rectification and voltage regulation circuit is connected to the output terminal of the LLC resonant module, and the output terminal of the rectification and voltage regulation circuit is connected to the output unit, which is used to rectify and filter the single-phase alternating current after voltage regulation to output low-ripple direct current.

[0054] Furthermore, the power conversion unit further includes a spike absorption capacitor. One end of the spike absorption capacitor is connected to the positive pole of the DC input terminal of the inverter module, and the other end is connected to the negative pole of the DC input terminal of the inverter module.

[0055] Figure 2 The case where there are two of the power conversion units is shown. Among them, in the power conversion unit at the upper position (for the convenience of subsequent description, it is called the first power conversion unit here), in this inverter module (referred to as the first inverter module here), the power switch tubes Q1 to Q4 form a classic single-phase inverter bridge circuit. The structure and working principle of the single-phase inverter bridge circuit are common knowledge and will not be elaborated here. A spike absorption capacitor C1 is connected in parallel at the DC input end of the first inverter module to absorb the possible spike voltage components in the high-ripple direct current and achieve a filtering effect.

[0056] Figure 2 The power conversion unit shown at the lower position is called the second power conversion unit here, and its inverter module is called the second inverter module. As Figure 2 shown, the second inverter module is composed of power switch tubes Q5 to Q8 to form a classic single-phase inverter bridge circuit, and its working principle is the same as that of the first inverter module and will not be elaborated here. A spike absorption capacitor C2 is connected in parallel at the DC input end of the second inverter module to absorb the possible spike voltage components in the high-ripple direct current and achieve a filtering effect.

[0057] Similarly, spike absorption capacitors can be connected in parallel at the front end of the inverter modules in each power conversion unit to reduce the ripple in the subsequent circuit.

[0058] Since in the actual implementation scenario, more power conversion units than Figure 2 shown may be used for ripple reduction processing. To obtain a better ripple reduction effect, in addition to reducing the current through multiple power conversion units, the ripple reduction effect can also be achieved by adjusting the switching frequency of the inverter module and controlling the working timing of the inverter modules in each of the power conversion units.

[0059] In one possible implementation manner, a better ripple reduction effect is achieved by adopting a method of sequentially turning on the inverter modules in each of the power conversion units in sequence. Specifically, the time interval t between the control signals of the inverter modules in two adjacent power conversion units satisfies the following conditions;

[0060] t = T * D / n,

[0061] where T is the period of the PWM signal, D is the duty cycle of the high level in the PWM signal, and n is the number of the power conversion units.

[0062] To better demonstrate the technical effect of this embodiment, as Figure 4 shown is a timing diagram of the control signals of each inverter module in the scenario where 6 power conversion units are set. PWM1 to PWM6 are the control signals of 6 inverter modules respectively, and there is a preset phase difference θ between the control signals of adjacent inverter modules. AsFigure 5 As shown in Figure 4 the simulation diagram of single-phase alternating current output by each inverter module under the shown control timing. From Figure 5 the multiple small-amplitude waveforms (A12 / A22 / A32 / A42 / A52 / A62) below, it can be seen that there is a certain phase difference between the single-phase alternating currents output by each inverter module. Figure 5 The waveform with a higher amplitude (A2) shown is the simulation waveform of single-phase alternating current obtained by using only one power conversion unit. Comparing it with the multiple small-amplitude waveforms output by the inverter modules below, the amplitude of the waveform below is about 1 / 6 of the amplitude of the waveform above. That is, the amount of amplitude reduction is related to the number of power conversion units. The more power conversion units, the lower the amplitude of the obtained single-phase alternating current. Finally, it is obtained that the amplitude of the ripple in the high-voltage direct current is positively correlated with the amplitude of the single-phase alternating current output by the inverter module here. From Figure 5 it can be seen that after rectifying and superimposing the single-phase alternating current through the subsequent circuit, the ripple amplitude will be significantly reduced. According to the rules of this embodiment, 6 power conversion units work according to the Figure 4 shown timing, and there is a phase difference between the conduction times of the inverter modules in adjacent two power conversion units.

[0063] Preferably, the power switch tubes Q1~Q8 can be implemented by MOSFETs. Compared with the scheme using IGBTs, using MOSFETs can use a higher operating frequency and make the peak value of the output current lower. Multiple inverter modules are connected in parallel, and all inverter modules are controlled in a staggered manner according to the Figure 4 shown rules, and the switching loss is reduced by multi-group mos staggered parallel connection, and the generation of ripple can be suppressed.

[0064] In one possible implementation manner, as Figure 2 shown, the LLC resonant module includes a resonant capacitor, a transformer and a resonant inductor. The resonant capacitor, the primary of the transformer and the resonant inductor are sequentially connected in series at the AC output end of the inverter module to form a loop, and the secondary of the transformer is connected to the rectifying and voltage-regulating circuit. For example, Figure 2 the LLC resonant module in the first power conversion unit includes a resonant capacitor Cr1, the primary of a transformer T1 ( Figure 2 not shown, which can be combined with Figure 3 the content) and a resonant inductor Lr1. Since the three are connected in series to the AC circuit of the first inverter module, the resonant capacitor Cr1, the primary leakage inductance Lm1 of the transformer T1 and the resonant inductor Lr1 form an LLC resonant circuit. Since Figure 2The second power conversion unit shown and the first power conversion unit are parallel circuits with the same structure. Similarly, the LLC resonant module in the second power conversion unit includes a resonant capacitor Cr2, the primary of a transformer T2 (not shown in the figure), and a resonant inductor Lr2. Since the three are connected in series to the AC circuit of the second inverter module, the resonant capacitor Cr2, the primary leakage inductance Lm2 of the transformer T2, and the resonant inductor Lr2 form an LLC resonant circuit.

[0065] The LLC resonant module can achieve efficient energy conversion at high frequencies. Combining the front-end inverter module and the rear-stage rectification and voltage regulation circuit, it can convert the DC power input to the inverter module into high-frequency AC power, and transmit it to the rear-stage rectification and voltage regulation circuit through a transformer. After rectification, voltage regulation, and filtering, high-voltage DC power with less ripple can be obtained.

[0066] Since the working principles of each power conversion unit are similar, the rectification and voltage regulation circuit in the first power conversion unit is used as an example for illustration here. Figure 2 In the first power conversion unit shown, single-phase AC power is transmitted to Figure 3 the shown rectification and voltage regulation circuit through the transformer T1.

[0067] In one possible implementation, as Figure 3 shown, the rectification and voltage regulation circuit includes a first energy storage capacitor C3, a second energy storage capacitor C4, a third energy storage capacitor C5, a fourth energy storage capacitor C6, a fifth energy storage capacitor C7, a sixth energy storage capacitor C8, and first rectifier diodes D1 to eighth rectifier diodes D8. The rectification and voltage regulation circuit is connected to the secondary of the transformer T1;

[0068] The secondary winding of the transformer T1 has a center tap. The center tap of the secondary winding of the transformer is sequentially connected in series with the first rectifier diodes D1 to fourth rectifier diodes D4 and then connected to the DC output terminal HV+. The center tap of the secondary winding of the transformer is also sequentially connected in series with the fifth rectifier diodes D5 to eighth rectifier diodes D8 and then connected to the DC output terminal; the cathodes of the first rectifier diodes D1 to eighth rectifier diodes D8 all face the DC output terminal HV+, and the anodes of the first rectifier diodes D1 to eighth rectifier diodes D8 all face the center tap of the secondary winding of the transformer; the center tap of the secondary winding of the transformer is also sequentially connected in series with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 and then connected to the DC output terminal HV+; the common nodes of the second rectifier diode D2 and the third rectifier diode D3, the common nodes of the sixth rectifier diode D6 and the seventh rectifier diode D7, and the common nodes of the third energy storage capacitor C5 and the fourth energy storage capacitor C6 are connected;

[0069] One end of the secondary winding of the transformer is connected to the common node of the third rectifying diode D3 and the fourth rectifying diode D4 after sequentially connecting the first energy storage capacitor C3 and the second energy storage capacitor C4 in series, and the common node of the first energy storage capacitor C3 and the second energy storage capacitor C4 is connected to the common node of the first rectifying diode D1 and the second rectifying diode D2;

[0070] The other end of the secondary winding of the transformer is connected to the common node of the seventh rectifying diode D7 and the eighth rectifying diode D8 after sequentially connecting the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 in series, and the common node of the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 is connected to the common node of the fifth rectifying diode D5 and the sixth rectifying diode D6.

[0071] It can be understood that the rectifying and voltage regulating circuit is a full-wave rectifying voltage doubling circuit, which is a symmetric circuit with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 as the midline. From Figure 3 the perspective of, since the upper end points of the upper segment winding and the lower segment winding of the secondary of the transformer T1 are respectively the same-name points as the upper end point of the primary winding of the transformer T1, the direction of the current I1 in the upper segment winding of the secondary of the transformer T1 is the same as the direction of the current I2 in the lower segment winding of the secondary of the transformer T1.

[0072] Based on the unidirectional conduction characteristic of the rectifying diode and the DC blocking characteristic of the capacitor, the working principle of the rectifying and voltage regulating circuit is briefly described as follows. As Figure 6As shown, in the negative half-cycle of the output waveform of transformer T1, the directions of the currents I1 and I2 output by the secondary winding of transformer T1 are both counterclockwise. When the rectifier voltage regulation circuit is in a steady-state operation state, the current I1 flows through the first rectifier diode D1 to charge the first energy storage capacitor C3, through the second rectifier diode D2 to charge the third energy storage capacitor C5, through the third rectifier diode D3 to charge the second energy storage capacitor C4, and through the fourth rectifier diode D4 to charge the fourth energy storage capacitor C6. At the same time, in this negative half-cycle, due to the DC-blocking characteristic of the capacitor, when the current I2 flows counterclockwise to the fifth energy storage capacitor C7, it is cut off. In this state, the fifth energy storage capacitor C7 is in a discharging state, and the fifth energy storage capacitor C7 discharges to the third energy storage capacitor C5 through the sixth rectifier diode D6, and also discharges to the sixth energy storage capacitor C8 through the sixth rectifier diode D6 and the seventh rectifier diode D7 in sequence, and also discharges to the fourth energy storage capacitor C6 through the sixth rectifier diode D6, the seventh rectifier diode D7 and the eighth rectifier diode D8 in sequence; the third energy storage capacitor C5 discharges to the sixth energy storage capacitor C8 through the seventh rectifier diode D7, and also discharges to the fourth energy storage capacitor C6 through the seventh rectifier diode D7 and the eighth rectifier diode D8 in sequence; the sixth energy storage capacitor C8 discharges to the fourth energy storage capacitor C6 through the eighth rectifier diode D8. Assuming that the output voltage of the secondary winding of the transformer is U, in this negative half-cycle, the charging current I1 from the transformer charges the first energy storage capacitor C3, the second energy storage capacitor C4, the third energy storage capacitor C5, and the fourth energy storage capacitor C6, and the charging voltage is U. At the same time, the fifth energy storage capacitor C7 discharges to the third energy storage capacitor C5 (the discharging voltage is U), and the discharging voltage U is superimposed on the charging voltage U, so that the voltage across the third energy storage capacitor C5 is 2U; the third energy storage capacitor C5 discharges to the sixth energy storage capacitor C8, and the fifth energy storage capacitor C7 discharges to the sixth energy storage capacitor C8, then the discharging voltage on the sixth energy storage capacitor C8 is superimposed to 2U, and the discharging voltage 2U is superimposed on the charging voltage U, so that the voltage of the high-voltage end of the sixth energy storage capacitor C8 with respect to the zero-potential point is 3U; the sixth energy storage capacitor C8 discharges to the fourth energy storage capacitor C6, the third energy storage capacitor C5 discharges to the fourth energy storage capacitor C6, and the fifth energy storage capacitor C7 discharges to the fourth energy storage capacitor C6 (the discharging voltage is superimposed to 3U), and the discharging voltage 3U is superimposed on the charging voltage U, so that the voltage of the high-voltage end of the fourth energy storage capacitor C6 with respect to the ground is 4U; finally, the high-voltage end of the fourth energy storage capacitor C6 outputs a high-voltage direct current after being boosted by 4 times.

[0073] Similarly, as Figure 7As shown, during the positive half-cycle of the output waveform of transformer T1, the directions of both current I1 and current I2 output from the secondary winding of transformer T1 are switched to the clockwise direction. In this state, the rectifying and voltage-regulating circuit acts as a symmetric circuit with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 as the midline, and the circuit operating states of the upper and lower parts of the midline are swapped. That is, the operating state of the first energy storage capacitor C3 is swapped with the operating state of the fifth energy storage capacitor C7, and the operating state of the second energy storage capacitor C4 is swapped with the operating state of the sixth energy storage capacitor C8. Specifically, during this positive half-cycle, due to the DC-blocking characteristic of the capacitor, when current I2 flows counterclockwise to the first energy storage capacitor C3, it is cut off. In this state, the first energy storage capacitor C3 is in the discharging state. The first energy storage capacitor C3 discharges to the third energy storage capacitor C5 through the second rectifying diode D2, and also discharges to the second energy storage capacitor C4 successively through the second rectifying diode D2 and the third rectifying diode D3, and also discharges to the fourth energy storage capacitor C6 successively through the second rectifying diode D2, the third rectifying diode D3, and the fourth rectifying diode D4; the third energy storage capacitor C5 discharges to the second energy storage capacitor C4 through the third rectifying diode D3, and also discharges to the fourth energy storage capacitor C6 successively through the third rectifying diode D3 and the fourth rectifying diode D4; the second energy storage capacitor C4 discharges to the fourth energy storage capacitor C6 through the fourth rectifying diode D4. At the same time, current I2 successively flows through the fifth rectifying diode D5 to charge the fifth energy storage capacitor C7, flows through the second rectifying diode D6 to charge the third energy storage capacitor C5, flows through the third rectifying diode D7 to charge the sixth energy storage capacitor C8, and flows through the fourth rectifying diode D8 to charge the fourth energy storage capacitor C6. Similar to the principle of the previous half-cycle, during this positive half-cycle, the charging current I2 from the transformer charges the fifth energy storage capacitor C7, the sixth energy storage capacitor C8, the third energy storage capacitor C5, and the fourth energy storage capacitor C6, and the charging voltage is U. At the same time, the first energy storage capacitor C3 discharges to the third energy storage capacitor C5 (the discharging voltage is U), and the discharging voltage U is superimposed on the charging voltage U, so that the voltage across the third energy storage capacitor C5 is 2U; the third energy storage capacitor C5 discharges to the second energy storage capacitor C4, and the first energy storage capacitor C3 discharges to the second energy storage capacitor C4 (the superimposed discharging voltage is 2U), and the discharging voltage 2U is superimposed on the charging voltage U, so that the voltage of the high-voltage end of the second energy storage capacitor C4 with respect to the zero-potential point is 3U; the second energy storage capacitor C4 discharges to the fourth energy storage capacitor C6, the third energy storage capacitor C5 discharges to the fourth energy storage capacitor C6, and the first energy storage capacitor C3 discharges to the fourth energy storage capacitor C6 (the superimposed discharging voltage is 3U), and the discharging voltage 3U is superimposed on the charging voltage U, so that the voltage of the high-voltage end of the fourth energy storage capacitor C6 with respect to the zero-potential point is 4U; finally, the high-voltage end of the fourth energy storage capacitor C6 outputs high-voltage direct current after 4-fold voltage boost. The low-voltage end of the third energy storage capacitor C5 (i.e., Figure 3 the left end of the third energy storage capacitor C5 shown) can be selected as the zero-potential point.

[0074] As a symmetrical circuit, the upper and lower parts of the rectifying and voltage-regulating circuit swap their working states every half cycle during each working cycle of the transformer, achieving full-wave rectification and simultaneously realizing multiple-fold regulation of the output voltage. During the processes of rectification and voltage multiplication regulation, due to the adoption of multi-stage capacitor filtering, the output ripple is effectively reduced, realizing the filtering of high-voltage direct current. The rectifying and voltage-regulating circuit of the solution in this embodiment adopts a full-wave rectification scheme, which further effectively reduces the ripple in the output high-voltage direct current compared with the traditional half-wave rectification voltage multiplication scheme, and the voltage stress of a single energy storage capacitor is smaller.

[0075] It is worth noting that in the rectifying and voltage multiplying circuit, usually every 2 times of voltage is called one order, represented by N. Figure 3 The circuit shown is a 2-order circuit, that is, N = 2. To meet the needs of actual implementation scenarios, more orders may be set in the rectifying and voltage-regulating circuit. For example, a 3-order 6-fold voltage rectifying circuit is set, and its basic working principle is the same as that of Figure 3 the circuit shown, which will not be elaborated here. If it is desired that the polarity of the output direct current voltage is different, just reverse all the rectifying diodes in the rectifying and voltage-regulating circuit.

[0076] In one possible implementation manner, the output unit includes a resistor R1, and the DC output terminal HV+ of all the rectifying and voltage-regulating circuits is connected in parallel with the resistor R1.

[0077] It can be understood that the resistor R1 can form an RC filtering circuit with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 to further filter out the AC components in the output high-voltage direct current, so as to achieve the effect of reducing the ripple.

[0078] In one possible implementation manner, as Figure 1 shown, the system further includes a feedback circuit, and the feedback circuit is used to detect the low-ripple direct current output by the rectifying and voltage-regulating circuit and / or the low-ripple high-voltage direct current output by the output unit. For example, the feedback circuit adopts a high-precision voltage sensor, which can accurately detect tiny voltage changes, and the feedback circuit gives an accurate feedback signal, which can be used as a reference factor for closed-loop control of the system.

[0079] Furthermore, as Figure 1 shown, the system further includes a control unit, the input end of the control unit is connected to the feedback circuit, and the output end of the control unit is connected to the control end of the inverter module, and is used to adjust the control signal of the inverter module according to the detection signal of the feedback circuit.

[0080] It can be understood that the control unit can adopt an intelligent control unit including a microcontroller MCU or a digital signal processor DSP, and a driving circuit, which can process data quickly and accurately to achieve precise control of the power output. The intelligent control unit combines the above-mentioned high-precision feedback circuit. During operation, the high-precision feedback circuit monitors the output voltage of the high-voltage power supply system in real time and transmits the monitoring signal to the intelligent control unit. The intelligent control unit uses a microcontroller MCU or a digital signal processor DSP to process the feedback signal according to a preset control algorithm, and adjusts the control signal to control the operating parameters of the power conversion circuit. For example, the control unit compares the feedback signal with a preset target voltage, calculates the error value, and adjusts the operating parameters of the power conversion circuit, such as the switching frequency and duty cycle of the inverter module, to achieve precise regulation of the output high-voltage DC voltage.

[0081] A low-ripple high-voltage power supply control system provided by the present utility model has the following advantages:

[0082] The output ripple of the high-voltage DC power supply is significantly reduced, the stability and reliability of the power supply are improved, and the requirements of equipment and application scenarios with high requirements for power quality can be met;

[0083] The optimized multiple parallel power conversion circuits are controlled in a time-division interleaved manner, effectively improving the efficiency of the power supply, reducing energy loss, reducing electromagnetic interference, and at the same time reducing the output ripple of the high-voltage DC power supply; the rectifier voltage regulator circuit in the power conversion circuit filters at multiple levels while rectifying and boosting by multiple times, further filtering the output ripple of the high-voltage DC power supply;

[0084] By adopting an intelligent control unit and a high-precision feedback circuit, real-time precise control of the power output is achieved, and the dynamic response performance of the power supply is improved.

[0085] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A low-ripple high-voltage power supply control system, characterized in that, It includes an input rectification unit, multiple power conversion units, and an output unit arranged in sequence. The multiple power conversion units are arranged in parallel between the input rectification unit and the output unit; The input rectification unit is used to rectify the input raw power supply to obtain high-ripple direct current; The multiple power conversion units are used to divide the high-ripple direct current into multiple paths of direct current to reduce the voltage, and then invert, regulate the voltage, and rectify the reduced high-ripple direct current in sequence to obtain multiple paths of low-ripple direct current; The output unit is used to superimpose the multiple paths of low-ripple direct current to output low-ripple high-voltage direct current.

2. The low-ripple high-voltage power supply control system according to claim 1, characterized in that The input rectification unit includes a first rectifier bridge and a first inductor. The AC input terminal of the first rectifier bridge is connected to an external power supply. The positive pole of the DC output terminal of the first rectifier bridge is connected in series with the first inductor. The end of the first inductor away from the first rectifier bridge serves as the positive output terminal of the input rectification unit, and the negative pole of the DC output terminal of the first rectifier bridge serves as the negative output terminal of the input rectification unit.

3. A low-ripple high-voltage power supply control system according to claim 1 or 2, characterized in that The power conversion unit includes an inverter module, an LLC resonance module, and a rectification and voltage regulation circuit arranged in sequence; The DC input terminal of the inverter module is connected to the output terminal of the input rectification unit, and the AC output terminal of the inverter module is connected to the LLC resonance module, which is used to invert the reduced high-ripple direct current into single-phase alternating current; The LLC resonance module is used to realize the soft start of the inverter module and also used to regulate the voltage of the single-phase alternating current and then output it; The input terminal of the rectification and voltage regulation circuit is connected to the output terminal of the LLC resonance module, and the output terminal of the rectification and voltage regulation circuit is connected to the output unit, which is used to rectify and filter the regulated single-phase alternating current to output low-ripple direct current.

4. A low-ripple high-voltage power supply control system according to claim 3, characterized in that, The power conversion unit also includes a spike absorption capacitor. One end of the spike absorption capacitor is connected to the positive pole of the DC input terminal of the inverter module, and the other end is connected to the negative pole of the DC input terminal of the inverter module.

5. A low-ripple high-voltage power supply control system according to claim 3, characterized in that, The time interval t between the control signals of the inverter modules in two adjacent power conversion units satisfies the following conditions; t = T * D / n, where T is the period of the PWM signal, D is the duty cycle of the high level in the PWM signal, and n is the number of power conversion units.

6. The low-ripple high-voltage power supply control system according to claim 3, characterized in that, The LLC resonance module includes a resonance capacitor, a transformer, and a resonance inductor. The resonance capacitor, the primary of the transformer, and the resonance inductor are connected in series in sequence at the AC output terminal of the inverter module to form a loop, and the secondary of the transformer is connected to the rectification and voltage regulation circuit.

7. A low-ripple high-voltage power supply control system according to claim 6, characterized in that, The rectification and voltage regulation circuit includes a first energy storage capacitor C3, a second energy storage capacitor C4, a third energy storage capacitor C5, a fourth energy storage capacitor C6, a fifth energy storage capacitor C7, a sixth energy storage capacitor C8, and first rectifier diodes D1 to eighth rectifier diodes D8. The rectification and voltage regulation circuit is connected to the secondary of the transformer T1; The secondary winding of the transformer T1 has a center tap. The center tap of the secondary winding of the transformer is sequentially connected in series with the first rectifier diode D1 to the fourth rectifier diode D4 and then connected to the DC output terminal HV+. The center tap of the secondary winding of the transformer is also sequentially connected in series with the fifth rectifier diode D5 to the eighth rectifier diode D8 and then connected to the DC output terminal; the cathodes of the first rectifier diode D1 to the eighth rectifier diode D8 all face the DC output terminal HV+, and the anodes of the first rectifier diode D1 to the eighth rectifier diode D8 all face the center tap of the secondary winding of the transformer; the center tap of the secondary winding of the transformer is also sequentially connected in series with the third energy storage capacitor C5 and the fourth energy storage capacitor C6 and then connected to the DC output terminal HV+; the common node of the second rectifier diode D2 and the third rectifier diode D3, the common node of the sixth rectifier diode D6 and the seventh rectifier diode D7, and the common node of the third energy storage capacitor C5 and the fourth energy storage capacitor C6 are connected; One end of the secondary winding of the transformer is sequentially connected in series with the first energy storage capacitor C3 and the second energy storage capacitor C4 and then connected to the common node of the third rectifier diode D3 and the fourth rectifier diode D4, and the common node of the first energy storage capacitor C3 and the second energy storage capacitor C4 is connected to the common node of the first rectifier diode D1 and the second rectifier diode D2; The other end of the secondary winding of the transformer is sequentially connected in series with the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 and then connected to the common node of the seventh rectifier diode D7 and the eighth rectifier diode D8, and the common node of the fifth energy storage capacitor C7 and the sixth energy storage capacitor C8 is connected to the common node of the fifth rectifier diode D5 and the sixth rectifier diode D6.

8. The low-ripple high-voltage power supply control system according to claim 7, characterized in that The output unit includes a resistor R1, and the DC output terminals HV+ of all the rectifier voltage regulating circuits are connected in parallel to the resistor R1.

9. A low-ripple high-voltage power supply control system according to claim 3, characterized in that, It further includes a feedback circuit, and the feedback circuit is used to detect the low-ripple direct current output by the rectifier voltage regulating circuit and / or the low-ripple high-voltage direct current output by the output unit.

10. A low-ripple high-voltage power supply control system according to claim 9, characterized in that, It further includes a control unit. The input end of the control unit is connected to the feedback circuit, and the output end of the control unit is connected to the control end of the inverter module, and is used to adjust the control signal of the inverter module according to the detection signal of the feedback circuit.

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