High-Voltage DC Circuit Topology

Abstract

The present invention discloses a high-voltage DC circuit topology. In the high-voltage DC circuit topology, the positive pole of the DC power supply DC is connected to the positive terminal of the bus capacitor C0 via the diode D1, and the negative pole is connected to the negative terminal of the bus capacitor C0; the positive terminal of the bus capacitor C0 is connected to the common drain of the fault current limiting unit and the full-bridge circuit, and the negative terminal is connected to the common source of the full-bridge circuit to form a radio frequency oscillator. The primary winding of the radio frequency transformer T1 is connected in parallel with the tuning capacitor C2. The radio frequency feed electrode a is connected to the a end of the first secondary winding of the radio frequency transformer, and the radio frequency feed electrode b is connected to the b end of the second secondary winding of the radio frequency transformer. A voltage multiplier is placed between the radio frequency feed electrode a and the radio frequency feed electrode b to achieve voltage superposition. The voltage multiplier is composed of a cascade of multiple radio frequency energy coupling electrodes and radio frequency rectifiers. One end of the parallel resonance filter is connected to the last-stage radio frequency energy coupling electrode of the voltage multiplier, and the other end is connected to the load to achieve a DC voltage with low ripple on the load.

Description

Technical Field

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

[0002] DC high-voltage power supplies can be used for DC withstand voltage tests on high-voltage electrical equipment such as DC cables, converter transformers, and arresters, and can also be used for ion implantation in semiconductor manufacturing, accelerator mass spectrometry analysis, etc. Currently, most of the DC high-voltage test power supplies used in traditional DC high-voltage tests adopt voltage multiplier circuits. As the requirement for the output voltage increases, the number of voltage multiplier circuit stages needs to be increased. However, when the number of stages increases to a certain value, further increasing the number of stages will not help to increase the output voltage and will increase the number of components. In addition, as the number of voltage multiplier circuit stages increases, the output voltage ripple of the DC high-voltage power supply will increase rapidly, while the efficiency of the power supply will decrease, and the volume of the power supply device will also increase. The present invention aims to solve the above problems.

[0003] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present invention, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art in this country. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention proposes a high-voltage DC circuit topology with a low ripple coefficient based on radio frequency resonance drive distributed energy coupling superposition.

[0005] The object of the present invention is achieved through the following technical solutions. A high-voltage DC circuit topology includes:

[0006] Improving the load-carrying capacity by adopting a radio frequency resonance driver;

[0007] Realizing the multiplication generation of DC high voltage through a radio frequency energy coupling voltage multiplier;

[0008] By adopting distributed capacitors, the coupling of energy is realized and the volume of the DC high-voltage power supply is reduced.

[0009] In the high-voltage DC circuit topology;

[0010] A DC power supply DC, whose positive pole is connected to the positive terminal of a bus capacitor C0 via a diode D1, and whose negative pole is connected to the negative terminal of the bus capacitor C0;

[0011] A bus capacitor C0, whose positive terminal is connected to a fault current limiting unit and the common drain of a full-bridge circuit, and whose negative terminal is connected to the common source of the full-bridge circuit to form a radio frequency oscillator. Among them, the full-bridge circuit includes a first bridge arm and a second bridge arm. The fault current limiting unit is used to limit the current in case of a short-circuit fault, and the full-bridge circuit is used to generate a radio frequency square wave;

[0012] A radio frequency transformer T1, whose primary winding is connected in parallel with a tuning capacitor C2. The m terminal of the primary winding is connected to the midpoint of the second bridge arm via a resonant filter for filtering. The n terminal of the primary winding is connected to the midpoint of the first bridge arm to generate a radio frequency voltage at the primary side of the radio frequency transformer T1. The first secondary winding of the radio frequency transformer T1 is connected in parallel with a tuning capacitor C3, and the second secondary winding of the radio frequency transformer T1 is connected in parallel with a tuning capacitor C4. The first secondary winding and the second secondary winding of the radio frequency transformer are connected in series and then connected in parallel with a tuning capacitor C5 to form a resonant network;

[0013] A distributed radio frequency energy coupling voltage multiplier, which includes;

[0014] A radio frequency feeding electrode a, which is connected to the a terminal of the first secondary winding of the radio frequency transformer;

[0015] A radio frequency feeding electrode b, which is connected to the b terminal of the second secondary winding of the radio frequency transformer;

[0016] A voltage multiplier, which is placed between the radio frequency feeding electrode a and the radio frequency feeding electrode b to achieve voltage superposition. The voltage multiplier is composed of a plurality of radio frequency energy coupling electrodes and radio frequency rectifiers connected in cascade. The capacitances of the radio frequency feeding electrode and the radio frequency energy coupling electrode are between several pF and more than ten pF, and the parasitic capacitance of the radio frequency rectifier is less than 1 pF;

[0017] A parallel resonant filter, one end of which is connected to the last-stage radio frequency energy coupling electrode of the voltage multiplier, and the other end is connected to a load to achieve a DC voltage with a ripple not greater than five ten-thousandths on the load.

[0018] In the high-voltage DC circuit topology described above, the fault current limiting unit includes;

[0019] An inductor L1;

[0020] A power electronic switch Q1, which is connected in series with the inductor L1;

[0021] An inductor L2, which is connected in parallel with the inductor L1 and the power electronic switch Q1.

[0022] In the high-voltage DC circuit topology described above, the same-named terminal of the winding of the inductor L1 is connected to the different-named terminal of the winding of the inductor L2. The different-named terminal of the winding of the inductor L1 is connected in series with the power electronic switch Q1 and then connected to the same-named terminal of the winding of the inductor L2. Under normal operating conditions, the power electronic switch Q1 is in the conducting state. When a fault occurs, the power electronic switch Q1 is disconnected, and the inductor L2 is connected in series to limit the fault current.

[0023] In the high-voltage DC circuit topology described above, the power electronic switch Q1 is a semiconductor switch device with a on-state resistance of several tens of milliohms.

[0024] In the described high - voltage DC circuit topology, the first arm includes a series connection of a high - voltage power electronic switch Q2 and a high - voltage power electronic switch Q4, the second arm includes a series connection of a high - voltage power electronic switch Q3 and a high - voltage power electronic switch Q5. When the power electronic switch operates in the RF switch state, the inverter modulation method adopts a modulation method with a 50% duty cycle, and the first arm is connected in parallel with the second arm.

[0025] In the described high - voltage DC circuit topology, the resonant filter includes a series connection of an inductor L3 and a capacitor C1.

[0026] In the described high - voltage DC circuit topology, the RF transformer T1 adopts a hollow transformer structure with a center - tapped secondary side, and the hollow transformer structure uses a sparse winding method to control the distance between turns and pancakes of the winding.

[0027] In the described high - voltage DC circuit topology, the tuning capacitors C3 and C4 are respectively composed of the distributed capacitance between the RF feeding electrodes a, b and the metal outer cylinder of the voltage multiplier.

[0028] In the described high - voltage DC circuit topology, the tuning capacitor C5 is composed of the distributed capacitance between the RF feeding electrodes a and b.

[0029] In the described high - voltage DC circuit topology, n conductors are arranged near the RF feeding electrodes a and b to act as RF energy coupling electrodes, and the n conductors are sequentially connected in series through n - 1 RF rectifiers in the same conduction direction, where n is a natural number greater than 1.

[0030] Compared with the prior art, the present invention has the following advantages: The present invention improves the load - carrying capacity by adopting an RF resonant driver, realizes the multiplication of DC high voltage through an RF energy - coupled voltage multiplier, realizes the coupling of energy and reduces the volume of the device by adopting distributed capacitance, reduces the damage to the test sample during discharge, and realizes a significant improvement in the ripple characteristic through the application of a resonant filter on the DC output side, having significant advantages in many aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] By reading the following detailed description of the preferred specific embodiments, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The accompanying drawings in the specification are only for the purpose of showing the preferred embodiments and are not considered as limiting the present invention. Obviously, the following - described drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0032] In the drawings:

[0033] Figure 1 is a schematic connection diagram of a high - voltage DC circuit topology according to an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of a distributed radio - frequency energy - coupled voltage multiplier structure of a high - voltage DC circuit topology according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of an experimental test waveform of the primary power supply of 16V of a high - voltage DC circuit topology according to an embodiment of the present invention.

[0036] The present invention will be further explained below in conjunction with the drawings and embodiments. Detailed implementation manners

[0037] The following will refer to the attached Figures 1 to 3 The specific embodiments of the present invention will be described in more detail. Although the specific embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0038] It should be noted that in the description of the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. The specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in functions of components as the criterion for distinction. As mentioned throughout the specification and claims, the term "comprising" or "including" is an open - ended term and should be interpreted as "including but not limited to". The subsequent description of the specification is for the purpose of implementing the preferred embodiments of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The protection scope of the present invention shall be defined by the appended claims.

[0039] For the convenience of understanding the embodiments of the present invention, the following will further explain with specific embodiments in conjunction with the drawings, and each drawing does not constitute a limitation on the embodiments of the present invention.

[0040] For better understanding, as Figures 1 to 3 shown, the high - voltage DC circuit topology includes,

[0041] A DC power supply DC, whose positive pole is connected to the positive terminal of the bus capacitor C0 via a diode D1, and the negative pole is connected to the negative terminal of the bus capacitor C0;

[0042] The bus capacitor C0, whose positive terminal is connected to the common drain of the fault current limiting unit and the full-bridge circuit, and the negative terminal of the bus capacitor C0 is connected to the common source of the full-bridge circuit to form a radio frequency oscillator. Among them, the full-bridge circuit includes a first bridge arm and a second bridge arm. The fault current limiting unit is used to limit the current in case of a short-circuit fault, and the full-bridge circuit is used to generate a radio frequency square wave;

[0043] The radio frequency transformer T1, whose primary winding is connected in parallel with the tuning capacitor C2. The m terminal of the primary winding is connected to the midpoint of the second bridge arm via a resonant filter for filtering. The n terminal of the primary winding is connected to the midpoint of the first bridge arm to generate a radio frequency voltage at the primary side of the radio frequency transformer T1. The first secondary winding of the radio frequency transformer T1 is connected in parallel with the tuning capacitor C3, and the second secondary winding of the radio frequency transformer T1 is connected in parallel with the tuning capacitor C4. The first secondary winding and the second secondary winding of the radio frequency transformer are connected in series and then connected in parallel with the tuning capacitor C5 to form a resonant network;

[0044] The distributed radio frequency energy coupling voltage multiplier, which includes,

[0045] The radio frequency feeding electrode a, which is connected to the a terminal of the first secondary winding of the radio frequency transformer,

[0046] The radio frequency feeding electrode b, which is connected to the b terminal of the second secondary winding of the radio frequency transformer,

[0047] The voltage multiplier, which is placed between the radio frequency feeding electrode a and the radio frequency feeding electrode b to achieve voltage superposition. The voltage multiplier is composed of a plurality of radio frequency energy coupling electrodes and radio frequency rectifiers connected in cascade. The capacitances of the radio frequency feeding electrode and the radio frequency energy coupling electrode are between several pF and more than a dozen pF, and the parasitic capacitance of the radio frequency rectifier is less than 1 pF,

[0048] The parallel resonant filter, one end of which is connected to the last-stage radio frequency energy coupling electrode of the voltage multiplier, and the other end is connected to the load to achieve a DC voltage with a ripple not greater than five ten-thousandths on the load.

[0049] In the preferred embodiment of the high-voltage DC circuit topology, the fault current limiting unit includes,

[0050] The inductor L1,

[0051] The power electronic switch Q1, which is connected in series with the inductor L1,

[0052] The inductor L2, which is connected in parallel with the inductor L1 and the power electronic switch Q1.

[0053] In the preferred embodiment of the high-voltage DC circuit topology described above, the same-named end of the inductor L1 winding is connected to the opposite-named end of the inductor L2 winding, and the opposite-named end of the inductor L1 winding is connected to the same-named end of the inductor L2 winding in series via the power electronic switch Q1. Under normal operating conditions, the power electronic switch Q1 is in the conducting state. When a fault occurs, the power electronic switch Q1 disconnects, and the inductor L2 is connected in series to limit the fault current.

[0054] In the preferred embodiment of the high-voltage DC circuit topology described above, the power electronic switch Q1 is a semiconductor switch device with a on-state resistance of dozens of milliohms.

[0055] In the preferred embodiment of the high-voltage DC circuit topology described above, the first arm includes the high-voltage power electronic switches Q2 and Q4 connected in series, and the second arm includes the high-voltage power electronic switches Q3 and Q5 connected in series. When the power electronic switches operate in the radio-frequency switch state, the inverter modulation method adopts a modulation method with a 50% duty cycle, and the first arm is connected in parallel with the second arm.

[0056] In the preferred embodiment of the high-voltage DC circuit topology described above, the resonant filter includes the inductor L3 and the capacitor C1 connected in series.

[0057] In the preferred embodiment of the high-voltage DC circuit topology described above, the radio-frequency transformer T1 adopts a hollow transformer structure with a center-tapped secondary side, and the hollow transformer structure adopts a sparse winding method to control the distance between turns and pancakes of the winding.

[0058] In the preferred embodiment of the high-voltage DC circuit topology described above, the tuning capacitors C3 and C4 are respectively constituted by the distributed capacitance between the radio-frequency feeding electrodes a and b and the metal outer cylinder of the voltage multiplier.

[0059] In the preferred embodiment of the high-voltage DC circuit topology described above, the tuning capacitor C5 is constituted by the distributed capacitance between the radio-frequency feeding electrodes a and b.

[0060] In the preferred embodiment of the high-voltage DC circuit topology described above, n conductors are arranged near the radio-frequency feeding electrodes a and b to act as radio-frequency energy coupling electrodes, and the n conductors are connected in series in the same conduction direction in sequence through n - 1 radio-frequency rectifiers, where n is a natural number greater than 1.

[0061] In one embodiment, as Figure 1As shown in the figure, the positive terminal of the high-stability DC power supply DC is connected to the positive terminal of the bus capacitor C0 via the diode D1, and the negative terminal is connected to the negative terminal of the bus capacitor C0. After passing through the fault current limiting unit composed of the inductor L1, L2, and the power electronic switch Q1, the positive terminal of the bus capacitor C0 is connected to the common drain of the full-bridge circuit composed of the high-voltage power electronic switches Q2, Q3, Q4, and Q5. The negative terminal of the bus capacitor C0 is connected to the common source of the full-bridge circuit composed of the high-voltage power electronic switches Q2, Q3, Q4, and Q5. The full-bridge circuit composed of the bus capacitor C0 and the power electronic switches Q2, Q3, Q4, and Q5 realizes the function of the RF oscillator. The midpoint of the second bridge arm in the full-bridge circuit composed of the power electronic switches Q2, Q3, Q4, and Q5 is filtered by the series resonant filter composed of the inductor L3 and the capacitor C1 and then connected to the m terminal of the primary winding of the RF transformer T1. The midpoint of the first bridge arm in the full-bridge circuit composed of the power electronic switches Q2, Q3, Q4, and Q5 is connected to the n terminal of the primary winding of the RF transformer T1, and a RF sinusoidal voltage is generated in the primary of the RF transformer T1; the primary of the RF transformer T1 is connected in parallel with the tuning capacitor C2, the first secondary winding of the RF transformer T1 is connected in parallel with the tuning capacitor C3, the second secondary winding of the RF transformer T1 is connected in parallel with the tuning capacitor C4, and the first secondary winding and winding 2 of the RF transformer are connected in series and then connected in parallel with the tuning capacitor C5. Through the resonant network composed of the inductance of the RF transformer winding and the capacitors C3, C4, and C5, and relying on the step-up function of the transformer T1 itself, the generation of RF high voltage is realized; the a terminal of the first secondary winding of the RF transformer and the b terminal of the second secondary winding of the transformer are respectively connected to the RF feeding electrode a and the RF feeding electrode b in the distributed RF energy coupling voltage multiplier. The distributed RF energy coupling voltage multiplier composed of a large number of RF energy coupling electrodes and RF rectifiers cascaded is placed between the RF feeding electrode a and the RF feeding electrode b for voltage superposition. The last-stage RF energy coupling electrode is connected to the load after passing through the parallel resonant filter composed of the inductor L4 and the capacitor C6, and a DC voltage with extremely low ripple is realized on the load.

[0062] As Figure 2 shown, the distributed RF energy coupling voltage multiplier is connected to the RF high voltage and the RF feeding electrode a and the RF feeding electrode b, generating a high-frequency alternating electric field between the RF feeding electrodes. By arranging n conductors near the RF feeding electrodes a and b to act as RF energy coupling electrodes, and connecting the n conductors in series in turn through n - 1 RF rectifiers in the same conduction direction, either forward or backward is acceptable. The parasitic capacitance of the RF rectifier is required to be less than 1 pF, and the capacitance between the RF energy coupling electrode and the RF feeding electrode ranges from several pF to more than a dozen pF.

[0063] As Figure 3As shown, when the primary DC source inputs 16V, the primary side voltage of the transformer is about 17V, while the single-side amplitude of the secondary side is about 530V. The turns ratio of the transformer is about 30. At this time, the DC voltage output is 15.8kV, and the voltage multiplication factor of the voltage multiplier cylinder is about 29.8.

[0064] In one embodiment, a high-voltage DC circuit topology with low ripple coefficient based on radio frequency resonance-driven distributed energy coupling superposition includes a DC power supply DC, a diode D1, a filter capacitor C0, high-voltage power electronic switches Q1, Q2, Q3, Q4, Q5, fault current-limiting inductors L1, L2, resonance inductors L3, L4, resonance capacitors C1, C2, C3, C4, C5, C6, a radio frequency transformer T1, radio frequency energy coupling capacitors C 0b 、C 1a 、C 2b 、C 3a 、……C nb ,radio frequency rectifier stacks D 01 、D 12 、D 23 、……D (n-1)n ,and a load Z. The positive pole of the high-stability DC power supply is connected to the positive terminal of the bus capacitor via a diode, and the negative pole is connected to the negative terminal of the bus capacitor. After the positive terminal of the bus capacitor passes through a fault current-limiting unit composed of an inductor and a power electronic switch Q1, it is connected to the common drain of the full-bridge circuit composed of high-voltage power electronic switches. The negative terminal of the bus capacitor is connected to the common source of the full-bridge circuit composed of high-voltage power electronic switches. The bus capacitor and the full-bridge circuit composed of power electronic switches realize the function of a radio frequency oscillator. The midpoint of the second bridge arm in the full-bridge circuit composed of power electronic switches is connected to the m terminal of the primary winding of the radio frequency transformer after being filtered by a series resonance filter composed of an inductor and a capacitor. The midpoint of the first bridge arm in the full-bridge circuit composed of power electronic switches is connected to the n terminal of the primary winding of the radio frequency transformer, and a radio frequency sinusoidal voltage is generated on the primary side of the radio frequency transformer; the primary side of the radio frequency transformer is connected in parallel with a tuning capacitor. The two windings of the secondary side of the radio frequency transformer are respectively connected in parallel with tuning capacitors C3 and C4. The first secondary winding and the second secondary winding of the radio frequency transformer are connected in series and then connected in parallel with tuning capacitor C5. Through the resonance network composed of the winding inductance of the radio frequency transformer and capacitors C3, C4, and C5, and relying on the voltage boosting function of the transformer T1 itself, the generation of radio frequency high voltage is realized; the a end of the first secondary winding of the radio frequency transformer and the b end of the second secondary winding of the transformer are respectively connected to the radio frequency feeding electrode a and the radio frequency feeding electrode b in the distributed radio frequency energy coupling voltage multiplier. The distributed radio frequency energy coupling voltage multiplier composed of a large number of radio frequency energy coupling electrodes and radio frequency rectifiers in cascade is placed between the radio frequency feeding electrode a and the radio frequency feeding electrode b for voltage superposition. The last-stage radio frequency energy coupling electrode is connected to the load after passing through a parallel resonance filter composed of an inductor L4 and a capacitor C6, and a DC voltage with extremely low ripple is realized on the load.

[0065] In one embodiment, there should be a strong magnetic coupling between inductors L1 and L2 in the fault current limiting unit. The same-named end of the winding of inductor L1 should be connected to the opposite-named end of the winding of inductor L2. The opposite-named end of the winding of inductor L1 should be connected to the same-named end of the winding of inductor L2 in series through a power electronic switch Q1. The power electronic switch Q1 should be a semiconductor switch device with an extremely low on-state resistance. Under normal operating conditions, the power electronic switch Q1 is in the conducting state. After inductors L1 and L2 are connected in parallel, due to the cancellation of magnetic fluxes, the inductance in series in the loop is extremely small. When a fault occurs, the power electronic switch Q1 disconnects, and inductor L2 is connected in series to limit the fault current. The radio frequency oscillator should be implemented by a full-bridge inverter circuit composed of high-voltage power electronic switches Q2, Q3, Q4, and Q5. The power electronic switches can be power devices such as SiC MOSFETs and CoolMOSs suitable for radio frequency operating conditions and operate in the radio frequency switching state. The inverter modulation method adopts a modulation method with a duty cycle of nearly 50%. The radio frequency square wave oscillation generated by the full-bridge inverter circuit composed of Q2, Q3, Q4, and Q5 is filtered by a series resonance circuit composed of inductor L3 and capacitor C1 to achieve the output of radio frequency sinusoidal oscillation.

[0066] In one embodiment, the radio frequency resonant transformer should adopt a hollow transformer structure with a center-tapped secondary side. The hollow transformer should adopt a sparse winding method to control the distance between turns and pancakes of the winding to reduce the influence of distributed capacitance. The primary winding is shunt-tuned with capacitor C2. The first secondary winding of radio frequency transformer T1 is shunt-tuned with capacitor C3, and the second secondary winding of radio frequency transformer T1 is shunt-tuned with capacitor C4. The first secondary winding and the second secondary winding of the radio frequency transformer are connected in series and then shunt-tuned with capacitor C5. Among them, capacitors C3 and C4 are respectively composed of the distributed capacitance between the radio frequency feeding electrode a, the radio frequency feeding electrode b, and the metal outer cylinder of the voltage multiplier. Capacitor C5 is composed of the distributed capacitance between the radio frequency feeding electrode a and the radio frequency feeding electrode b. The shunt-tuned capacitors of the primary and secondary sides and the primary and secondary side inductors of the transformer form a radio frequency parallel resonance. The output of the radio frequency oscillator is connected to the radio frequency resonant transformer through a series resonance circuit composed of a hollow inductor L3 and a capacitor C1 in series to increase the input port voltage of the radio frequency resonant transformer. By optimizing the radio frequency parallel resonance impedance formed by the shunt-tuned capacitors of the primary and secondary sides and the primary and secondary side inductors of the transformer, the current stress of the inverter is reduced. For the distributed radio frequency energy coupling voltage multiplier, the radio frequency high voltage should be connected to the radio frequency feeding electrode a and the radio frequency feeding electrode b to generate a high-frequency alternating electric field between the radio frequency feeding electrodes. By arranging n conductors near the radio frequency feeding electrodes a and b as radio frequency energy coupling electrodes, and connecting the n conductors in series in sequence through n - 1 radio frequency rectifiers in the same conduction direction (either forward or negative), the parasitic capacitance requirement of the radio frequency rectifier is less than 1 pF, and the capacitance between the radio frequency energy coupling electrode and the radio frequency feeding electrode should be in the range of several pF to more than a dozen pF.

[0067] Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A high-voltage DC circuit topology, characterized in that: The load-carrying capacity is improved by adopting a radio frequency resonant driver; The multiplication generation of DC high voltage is realized through a radio frequency energy coupling voltage multiplier; By adopting distributed capacitors, energy coupling is realized and the volume of the DC high-voltage power supply is reduced. A DC power supply DC, whose positive pole is connected to the positive terminal of the bus capacitor C0 via a diode D1, and the negative pole is connected to the negative terminal of the bus capacitor C0; A bus capacitor C0, whose positive terminal is connected to one end of a fault current-limiting unit, the other end of the fault current-limiting unit is connected to the common drain of a full-bridge circuit, and the negative terminal of the bus capacitor C0 is connected to the common source of the full-bridge circuit to form a radio frequency oscillator, wherein the full-bridge circuit includes a first bridge arm and a second bridge arm; the fault current-limiting unit is used to limit the current in case of a short-circuit fault, and the full-bridge circuit is used to generate a radio frequency square wave; A radio frequency transformer T1, whose primary winding is connected in parallel with a tuning capacitor C2, the m terminal of the primary winding is connected to the midpoint of the second bridge arm via a resonant filter for filtering, the n terminal of the primary winding is connected to the midpoint of the first bridge arm to generate a radio frequency voltage at the primary side of the radio frequency transformer T1, the first secondary winding of the radio frequency transformer T1 is connected in parallel with a tuning capacitor C3, the second secondary winding of the radio frequency transformer T1 is connected in parallel with a tuning capacitor C4, and the first secondary winding and the second secondary winding of the radio frequency transformer are connected in series and then connected in parallel with a tuning capacitor C5 to form a resonant network; A distributed radio frequency energy coupling voltage multiplier, which includes A radio frequency feeding electrode a, which is connected to the a terminal of the first secondary winding of the radio frequency transformer; A radio frequency feeding electrode b, which is connected to the b terminal of the second secondary winding of the radio frequency transformer; A voltage multiplier, which is placed between the radio frequency feeding electrode a and the radio frequency feeding electrode b to realize voltage superposition, and the voltage multiplier is composed of a plurality of radio frequency energy coupling electrodes and radio frequency rectifiers connected in cascade; A parallel resonant filter, one end of which is connected to the last-stage radio frequency energy coupling electrode of the voltage multiplier, and the other end is connected to a load to realize a DC voltage with a ripple not greater than five ten-thousandths on the load.

2. The high-voltage DC circuit topology according to claim 1, wherein, The fault current-limiting unit includes An inductor L1; A power electronic switch Q1, which is connected in series with the inductor L1; An inductor L2, which is connected in parallel with the inductor L1 and the power electronic switch Q1.

3. The high-voltage DC circuit topology according to claim 2, wherein, The same-named end of the winding of the inductor L1 is connected to the different-named end of the winding of the inductor L2, and the different-named end of the winding of the inductor L1 is connected in series with the power electronic switch Q1 and then connected to the same-named end of the winding of the inductor L2. Under normal operating conditions, the power electronic switch Q1 is in the conducting state. When a fault occurs, the power electronic switch Q1 is turned off, and the inductor L2 is connected in series to limit the fault current.

4. The high-voltage DC circuit topology according to claim 2, wherein, The power electronic switch Q1 is a semiconductor switch device with a on-state resistance of dozens of milliohms.

5. The high-voltage DC circuit topology according to claim 1, wherein, The first bridge arm includes a series-connected high-voltage power electronic switch Q2 and a high-voltage power electronic switch Q4, the second bridge arm includes a series-connected high-voltage power electronic switch Q3 and a high-voltage power electronic switch Q5. When the power electronic switches operate in the radio frequency switch state, the inverter modulation method adopts a modulation method with a 50% duty cycle, and the first bridge arm is connected in parallel with the second bridge arm.

6. The high-voltage DC circuit topology according to claim 5, wherein, The resonant filter includes a series-connected inductor L3 and a capacitor C1.

7. The high-voltage DC circuit topology according to claim 1, wherein, The RF transformer T1 adopts a center-tapped air-core transformer structure on the secondary side, and the air-core transformer structure uses a sparse winding method to control the distance between turns and pancakes of the winding.

8. The high-voltage DC circuit topology according to claim 1, wherein, The tuning capacitors C3 and C4 are respectively formed by the distributed capacitance between the RF feeding electrode a, the RF feeding electrode b and the metal outer cylinder of the voltage multiplier.

9. According to the high-voltage DC circuit topology described in claim 1, wherein, The tuning capacitor C5 is formed by the distributed capacitance between the RF feeding electrode a and the RF feeding electrode b.

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