High-voltage pulse generator, power supply and system for electrostatic dust collection

Abstract

The utility model relates to a high-voltage pulse generator for electrostatic dust collection, a power supply and a system, and relates to the technical field of dust collection equipment, the high-voltage pulse generator comprises a rectifier, an inverter and a Marx generator; the rectifier is connected with the inverter, and the inverter is coupled with the Marx generator; the rectifier is used for being connected with a three-phase alternating current power supply; the Marx generator is used for being coupled with an electrostatic dust collector; the rectifier is used for rectifying three-phase alternating current output by the three-phase alternating current power supply into direct current and outputting the direct current to the inverter; the inverter is used for inverting the direct current into high-frequency alternating current and outputting the high-frequency alternating current to the Marx generator; the Marx generator is used for converting the high-frequency alternating current into high-voltage pulses and outputting the high-voltage pulses to the electrostatic dust collector, and the high-voltage pulse generator can improve the dust collection efficiency through high voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of dust removal equipment, and more particularly, to a high-voltage pulse generator, a power supply, and a system for electrostatic dust removal. Background Art

[0002] With the increasing diversification of coal types burned in coal-fired power plants and the influence of factors such as co-incineration of urban sludge, the problem of excessive dust content in the inlet flue gas has become increasingly prominent. However, in related electrostatic precipitation technologies, the voltage levels provided by high-frequency power supplies are relatively low, making it difficult to meet the increasingly stringent dust removal requirements. Summary of the Utility Model

[0003] To solve the above problems, the present disclosure provides a high-voltage pulse generator, a power supply, and a system for electrostatic dust removal.

[0004] In a first aspect, the present disclosure provides a high-voltage pulse generator for electrostatic dust removal, including a rectifier, an inverter, and a Marx generator;

[0005] The rectifier is connected to the inverter, and the inverter is coupled to the Marx generator;

[0006] The rectifier is used to connect to a three-phase AC power supply;

[0007] The Marx generator is used to connect to an electrostatic precipitator;

[0008] The rectifier is configured to rectify the three-phase alternating current output by the three-phase AC power supply into direct current and output the direct current to the inverter;

[0009] The inverter is configured to invert the direct current into high-frequency alternating current and output the high-frequency alternating current to the Marx generator;

[0010] The Marx generator is configured to convert the high-frequency alternating current into high-voltage pulses and output the high-voltage pulses to the electrostatic precipitator.

[0011] Optionally, the Marx generator includes a trigger circuit, a multi-stage charge and discharge circuit, and a discharge isolation winding;

[0012] The trigger circuit is respectively connected to each stage of the charge and discharge circuit;

[0013] The multi-stage charge and discharge circuit is connected end to end in sequence;

[0014] The primary charge and discharge circuit and the final charge and discharge circuit in the multi-stage charge and discharge circuit are respectively connected to both ends of the discharge isolation winding;

[0015] The boost isolation winding of the inverter is respectively coupled to each stage of the charge and discharge circuit;

[0016] The discharge isolation winding is used for coupling with the electrostatic precipitator.

[0017] Optionally, each stage of the charging and discharging circuit includes:

[0018] Charging isolation winding, first protection resistor, charging capacitor, discharge switch tube and discharge capacitor;

[0019] The charging isolation winding, the charging capacitor and the first protection resistor are connected end to end in sequence to form a closed loop;

[0020] The charging capacitor is connected in parallel with the discharging capacitor;

[0021] The discharge switch tube is connected between the charging capacitor and the discharge capacitor, the input end of the discharge switch tube is connected to the charging capacitor, and the output end of the discharge switch tube is coupled to the discharge capacitor;

[0022] The discharge capacitor is used to store the electric energy of the charging capacitor when the discharge switch tube is turned on, and transmit the high-voltage pulse to the discharge isolation winding to prevent the charging capacitor from being damaged by the high-voltage pulse.

[0023] Optionally, the discharge capacitor of the primary charge-discharge circuit, the discharge capacitors of the remaining charge-discharge circuits at each stage, the discharge capacitor of the final charge-discharge circuit, and the discharge isolation winding are sequentially connected in series to form a closed loop;

[0024] The trigger circuit is respectively connected to the control end of the discharge switch tube of each stage of the charge and discharge circuit;

[0025] The boost isolation winding of the inverter is respectively coupled to the charging isolation winding of each stage of the charging and discharging circuit.

[0026] Optionally, each stage of the charging and discharging circuit further includes a filter inductor;

[0027] The filter inductor is connected between the output end of the discharge switch tube and the discharge capacitor;

[0028] The filter inductor is used for filtering to stabilize the voltage of the charging and discharging circuit.

[0029] Optionally, each stage of the charging and discharging circuit further includes a freewheeling diode;

[0030] The freewheeling diode is connected in parallel with the charging capacitor, and the cathode of the freewheeling diode is connected to the output end of the discharge switch tube;

[0031] The freewheeling diode is used to maintain the conduction state between the upper-stage charge-discharge circuit and the next-stage charge-discharge circuit of the current-stage charge-discharge circuit when a fault occurs in the current-stage charge-discharge circuit.

[0032] Optionally, each level of the charge and discharge circuit further includes a second protection resistor;

[0033] The second protection resistor is connected in series with the freewheeling diode, and the second protection resistor is connected to the anode of the freewheeling diode;

[0034] The second protection resistor is used to protect the freewheeling diode.

[0035] Optionally, the inverter includes a PWM signal generator, a full-bridge ZVT-PWM circuit, and a step-up isolation winding;

[0036] The PWM signal generator, the full-bridge ZVT-PWM circuit, and the step-up isolation winding are connected in sequence;

[0037] The full-bridge ZVT-PWM circuit is connected to the rectifier;

[0038] The step-up isolation winding is coupled to the charging isolation winding of the Marx generator;

[0039] The full-bridge ZVT-PWM circuit is used to achieve zero-voltage turn-on of the leg switching transistors and zero-current turn-on of the body diodes in the full-bridge ZVT-PWM circuit, so as to reduce the losses of the leg switching transistors and the body diodes.

[0040] In a second aspect, the present disclosure further provides a high-voltage pulse power supply for electrostatic precipitation, including:

[0041] A three-phase AC power supply and the high-voltage pulse generator as described in any one of the first aspect;

[0042] The three-phase AC power supply is connected to the rectifier of the high-voltage pulse generator.

[0043] In a second aspect, the present disclosure further provides an electrostatic precipitation system, including:

[0044] A three-phase AC power supply, an electrostatic precipitator, and the high-voltage pulse generator as described in any one of the first aspect;

[0045] The three-phase AC power supply is connected to the rectifier of the high-voltage pulse generator;

[0046] The Marx generator of the high-voltage pulse generator is coupled to the electrostatic precipitator.

[0047] Through the above technical solution, the rectifier converts three-phase alternating current into direct current, the inverter converts direct current into high-frequency alternating current, and the Marx generator converts high-frequency alternating current into high-voltage pulses. As the last-stage circuit, the Marx generator can generate high-voltage pulses up to dozens of kilovolts, providing sufficient discharge voltage for the electrostatic precipitator and facilitating the improvement of dust collection efficiency.

[0048] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. Brief Description of the Drawings

[0049] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0050] Figure 1 is a structural diagram of a high-voltage pulse generator for electrostatic dust removal shown according to an exemplary embodiment;

[0051] Figure 2 is a structural diagram of a Marx generator shown according to an exemplary embodiment;

[0052] Figure 3 is a structural diagram of an inverter shown according to an exemplary embodiment.

[0053] Description of the Reference Numerals in the Drawings

[0054] Three-phase AC power supply 8, electrostatic precipitator 9, rectifier 1, inverter 2, Marx generator 3, trigger circuit 301, discharge isolation winding 302, primary charge and discharge circuit 31, single-stage charge and discharge circuit 3i, final-stage charge and discharge circuit 3n, charge isolation winding 3i1, first protection resistor 3i2, charge capacitor 3i3, discharge switch tube 3i4, input end of the discharge switch tube 3i41, output end of the discharge switch tube 3i42, control end of the discharge switch tube 3i43, discharge capacitor 3i5, filter inductor 3i6, freewheeling diode 3i7, second protection resistor 3i8, PWM signal generator 21, full-bridge ZVT-PWM circuit 22, boost isolation winding 23, first inductor 225, second inductor 227, first switch tube 2211, first diode 2212, first capacitor 2213, second switch tube 2221, second diode 2222, second capacitor 2223, third switch tube 2231, third diode 2232, third capacitor 2233, fourth switch tube 2241, fourth diode 2242, fourth capacitor 2243, fifth capacitor 226. Detailed Description of the Invention

[0055] The following will describe in detail the specific embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present disclosure, and are not intended to limit the present disclosure.

[0056] The electrostatic precipitator 9 is a flue gas purification device for industrial use, which uses the electrostatic principle to capture dust particles. The high-voltage pulse generator can convert the three-phase AC power supply 8 into high-voltage pulses for the electrostatic precipitator 9.

[0057] Figure 1 It is a structural diagram of a high-voltage pulse generator for electrostatic precipitation shown according to an exemplary embodiment. As Figure 1 shown, the high-voltage pulse generator includes a rectifier 1, an inverter 2, and a Marx generator 3; the rectifier 1 is connected to the inverter 2, and the inverter 2 is coupled to the Marx generator 3; the rectifier 1 is used to connect to the three-phase AC power supply 8; the Marx generator 3 is used to connect to the electrostatic precipitator 9; the rectifier 1 is used to rectify the three-phase alternating current output by the three-phase AC power supply 8 into direct current, and output the direct current to the inverter 2; the inverter 2 is used to invert the direct current into high-frequency alternating current, and output the high-frequency alternating current to the Marx generator 3; the Marx generator 3 is used to convert the high-frequency alternating current into high-voltage pulses, and output the high-voltage pulses to the electrostatic precipitator 9.

[0058] Here, the rectifier 1 can be a three-phase full-wave rectifier circuit or a three-phase bridge rectifier circuit.

[0059] The inverter 2 can be a high-frequency inverter circuit composed of insulated gate bipolar transistors (IGBTs) or other switching tubes, and specifically can be a full-bridge inverter circuit, a series resonance inverter circuit, a multilevel inverter circuit, and a pulse-width modulation (PWM) inverter circuit, etc.

[0060] The Marx generator 3 is a special high-voltage pulse generating circuit, which uses the principle of parallel charging and series discharging of capacitors to convert high-frequency alternating current into high-voltage pulses. Such high-voltage pulses can provide the required high voltage for the electrostatic precipitator 9, help generate a strong electric field, and capture dust particles.

[0061] Generally, the operating voltage of the electrostatic precipitator 9 is between dozens and hundreds of kilovolts. Within this operating voltage range, the higher the voltage applied to the electrostatic precipitator 9, the stronger the electric field intensity generated. The stronger the electric field intensity, the greater the adsorption force on dust particles, and the higher the capture efficiency. And the pulsed voltage has a better dust collection effect than the DC voltage.

[0062] Figure 2 is a structural diagram of the Marx generator 3 shown according to an exemplary embodiment. In one embodiment, as Figure 2 shown, the Marx generator 3 includes a trigger circuit 301, a multi-stage charge and discharge circuit, and a discharge isolation winding 302; the trigger circuit 301 is respectively connected to each stage of the charge and discharge circuit; the multi-stage charge and discharge circuits are connected end to end in sequence; the primary charge and discharge circuit 31 and the last-stage charge and discharge circuit 3n in the multi-stage charge and discharge circuit are respectively connected to both ends of the discharge isolation winding 302; the boost isolation winding 23 of the inverter 2 is respectively coupled to each stage of the charge and discharge circuit; the discharge isolation winding 302 is used to be coupled to the electrostatic precipitator 9.

[0063] Here, the trigger circuit 301 can provide a trigger signal for the multi-stage charge and discharge circuit to start the discharge process of the entire Marx generator 3. The trigger signal can specifically be a pulse signal. Therefore, the trigger circuit 301 can specifically be a monostable trigger circuit for generating a pulse signal generator, an RC charge and discharge type single pulse generator, a 555 timer trigger circuit, etc.

[0064] The charge and discharge circuit can complete the charging and discharging processes of the capacitor, thereby generating a high-voltage pulse output. The charge and discharge circuit can specifically be a simple RC charge and discharge circuit, a switch-driven charge and discharge circuit, an energy transfer type charge and discharge circuit, a programmable charge and discharge circuit, etc. As Figure 2 shown, the primary charge and discharge circuit 31, the last-stage charge and discharge circuit 3n, and the single-stage charge and discharge circuit 3i are listed. Each stage of the charge and discharge circuit is Figure 2 the single-stage charge and discharge circuit 3i in. The label i in the figure can be 1, 2, 3... n, where n is an integer greater than or equal to 2. The multi-stage charge and discharge circuit can specifically be 2 to 20 single-stage charge and discharge circuits, and the structure of each stage of the charge and discharge circuit 3i is the same. The multi-stage charge and discharge circuit is synchronously driven and controlled by the trigger circuit 301. Each stage of the charge and discharge circuit 3i can generate an output voltage of up to 6 kV. Finally, the output voltage amplitude of the Marx generator 3 is the sum of the output voltages of all single-stage charge and discharge circuits 3i, which can be as high as dozens or hundreds of kV.

[0065] The discharge isolation winding 302 can couple the high-voltage pulse signal generated by the Marx generator 3 to the load end, and at the same time isolate the high-voltage output end of the Marx generator 3 from the load (such as the electrostatic precipitator 9). The discharge isolation winding 302 can specifically be the low-voltage winding in a transformer structure composed of a high-voltage winding and a low-voltage winding, and can also be a coupling transformer specifically designed for high-voltage pulse signals.

[0066] The high-voltage pulses generated by the Marx generator 3 can be as high as dozens or hundreds of kV, and there will be potential safety hazards if directly connected to the electrostatic precipitator 9. The discharge isolation winding 302 can act as a high-voltage transformer or coupling coil, and transmit the high-voltage pulse signal output by the Marx generator 3 to the electrostatic precipitator 9 through electromagnetic coupling.

[0067] In one embodiment, as Figure 2 shown, each charge-discharge circuit 3i includes: a charging isolation winding 3i1, a first protection resistor 3i2, a charging capacitor 3i3, a discharge switch tube 3i4, and a discharge capacitor 3i5; the charging isolation winding 3i1, the charging capacitor 3i3, and the first protection resistor 3i2 are connected end to end in sequence to form a closed loop; the charging capacitor 3i3 is connected in parallel with the discharge capacitor 3i5; the discharge switch tube 3i4 is connected between the charging capacitor 3i3 and the discharge capacitor 3i5, the input end 3i41 of the discharge switch tube is connected to the charging capacitor 3i3, and the output end 3i42 of the discharge switch tube is coupled to the discharge capacitor 3i5; the discharge capacitor 3i5 is used to store the electrical energy of the charging capacitor 3i3 and transmit a high-voltage pulse to the discharge isolation winding 302 when the discharge switch tube 3i4 is turned on, so as to prevent the charging capacitor 3i3 from being damaged by the high-voltage pulse.

[0068] Here, the charging isolation winding 3i1 can specifically be a transformer winding, which is used to provide a charging voltage for the single-stage charge-discharge circuit and provide insulation isolation. By setting a charging isolation winding 3i1 for each charge-discharge circuit separately, independent charging of the single-stage circuit can be achieved. If only one charging isolation winding 3i1 is set on the entire Marx generator 3, then all single-stage charge-discharge circuits 3i will be connected together, and independent charging and control cannot be realized. However, by setting a charging isolation winding 3i1 in each single-stage charge-discharge circuit 3i, the charging process of each stage can be independently controlled. If a certain stage of the charge-discharge circuit fails, it will not affect the charge-discharge circuits of other stages.

[0069] The first protection resistor 3i2 can protect the charging capacitor 3i3 and prevent the charging capacitor 3i3 from being damaged by high-voltage pulses. Specifically, when the discharge switch tube 3i4 is turned on, the discharge capacitor 3i5 will discharge a high-voltage pulse. Without the first protection resistor 3i2, the high-voltage pulse may damage the charging capacitor 3i3, and the first protection resistor 3i2 can limit the impact of this high-voltage pulse on the charging capacitor 3i3. Therefore, in order to achieve a better protection function, the first protection resistor 3i2 can specifically be a high-voltage and high-power metal oxide film resistor.

[0070] The discharge switch tube 3i4 can be used to control the discharge process of the charging capacitor 3i3. When the discharge switch tube 3i4 is turned on, the electric energy of the charging capacitor 3i3 can be quickly released to the discharge capacitor 3i5. The discharge switch tube 3i4 can be a power semiconductor device, such as an IGBT, a metal-oxide-semiconductor field-effect transistor (MOSFET), a gate turn-off thyristor (GTO), etc. Preferably, the discharge switch tube 3i4 can be an IGBT. The above three power semiconductor devices all have three terminals: a control terminal, an input terminal, and an output terminal. Among them, the control terminal, input terminal, and output terminal of the IGBT and GTO are the gate (Gate), the emitter (Emitter), and the collector (Collector), respectively. The control terminal, input terminal, and output terminal of the MOSFET are the gate (Gate), the source (Source), and the drain (Drain), respectively.

[0071] The charging capacitor 3i3 can be used to store the electric energy charged from the charging isolation winding 3i1. The discharging capacitor 3i5 can be used to store the electric energy accumulated when the charging capacitor 3i3 is charged. When the discharging switch tube 3i4 is turned on, the discharging capacitor 3i5 can release the electric energy. The charging capacitor 3i3 and the discharging capacitor 3i5 can be high-voltage capacitors with large capacity and high power, such as oil-immersed capacitors, polypropylene capacitors, metallized polypropylene capacitors, ceramic capacitors, etc.

[0072] When all the discharge switch tubes 3i4 are turned on at the same time, the charging capacitors 3i3 at each level will synchronously charge the electric energy into the discharge capacitors 3i5. The discharge capacitors 3i5 are prone to breakdown when subjected to high voltage pulses, and this damage is easier to repair than the charging capacitors 3i3. Because the discharge capacitors 3i5 are connected in series to the load (electrostatic precipitator 9), they are easier to replace. That is, the discharge capacitors 3i5 indirectly protect the charging capacitors 3i3.

[0073] The charging capacitor 3i3 is located at the input side of the Marx generator 3 and is the core component of the circuit. The installation position of the charging capacitor 3i3 may be more hidden or compact, and a certain structure needs to be disassembled to be replaced, which is often more troublesome than the discharge capacitor 3i5. If the charging capacitor 3i3 is damaged, it means that the entire Marx generator 3 cannot obtain the required charging voltage from the input side. The entire circuit will not work properly and may cause serious performance degradation or even complete failure. The discharge capacitor 3i5 is located at the output side, which is easier to maintain and replace. Even if it is damaged, it will not cause the entire Marx generator 3 to lose its working ability completely.

[0074] In related technologies, high-frequency power supplies usually include a secondary rectification circuit. If the secondary rectification circuit fails, it usually causes the entire high-frequency power supply to stop operating. By adopting the charge-discharge circuit structure of the Marx generator 3, this problem of the secondary rectification circuit can be avoided. Since the output of the Marx generator 3 is a high-voltage pulse and does not require a rectification circuit, even if the secondary rectification circuit fails, it will not affect the normal operation of the Marx generator 3.

[0075] In one embodiment, the discharge capacitors of the primary charge-discharge circuit 31, the discharge capacitors of the remaining levels of the charge-discharge circuits, the discharge capacitor of the last-stage charge-discharge circuit 3n, and the discharge isolation winding 302 are connected in series in sequence and form a closed loop; the trigger circuit 301 is respectively connected to the control ends of the discharge switch tubes of each level of the charge-discharge circuit; the step-up isolation winding 23 of the inverter 2 is respectively coupled to the charging isolation windings 3i1 of each level of the charge-discharge circuit.

[0076] Here, the discharge capacitors of the primary, intermediate levels, and the last stage are connected in series to form a closed circuit, so that the energy stored in the discharge capacitors of each level can be sequentially transferred to the discharge isolation winding 302 of the last stage, thereby realizing the synchronous discharge output of the entire Marx generator 3.

[0077] The trigger circuit 301 is respectively connected to the discharge switch tubes 3i4 of each level of the charge-discharge circuit and can be used to precisely control the conduction time of the discharge switch tubes 3i4 of each level, so that the charge-discharge circuits of each level of the Marx generator 3 can discharge synchronously.

[0078] The step-up isolation winding 23 of the inverter 2 (as Figure 3 shown) is respectively coupled to the charging isolation windings 3i1 of each level of the charge-discharge circuit, so that a charging voltage can be provided independently for each level, which is beneficial to realizing the independent control of the single-stage charge-discharge circuit 3i.

[0079] In one embodiment, as Figure 2 shown, each level of the charge-discharge circuit 3i further includes a filter inductor 3i6; the filter inductor 3i6 is connected between the output end 3i42 of the discharge switch tube and the discharge capacitor 3i5; the filter inductor 3i6 is used for filtering to stabilize the voltage of the charge-discharge circuit.

[0080] Here, the filter inductor 3i6 can specifically be composed of a wire wound on an iron core or an air-core winding, an iron-core inductor made of ferrite or powder iron-core material, a planar inductor made by a thin-film process, etc. Here, the filter inductor 3i6 and the charging capacitor 3i3 form an LC filter circuit, which can realize filtering of a wide frequency band.

[0081] In one embodiment, each level of the charging and discharging circuit 3i also includes a freewheeling diode 3i7; the freewheeling diode 3i7 is connected in parallel with the charging capacitor 3i3, and the cathode of the freewheeling diode 3i7 is connected to the output end 3i42 of the discharge switch tube; the freewheeling diode 3i7 is used to maintain the conduction state between the previous level charging and discharging circuit and the next level charging and discharging circuit of the current level charging and discharging circuit when a fault occurs in the current level charging and discharging circuit.

[0082] Here, the freewheeling diode 3i7 can be a fast recovery diode, a GTO diode, a silicon carbide Si or SiC diode. Preferably, it can be a fast recovery diode, which has fast switching characteristics, can withstand high-frequency high-voltage pulses, and is suitable for high-frequency switching circuits such as Marx generators.

[0083] If a single-stage charge-discharge circuit 3i fails, such as the charging capacitor 3i3 is damaged, the single-stage charge-discharge circuit 3i will not work properly, and the entire Marx generator 3 will be paralyzed. In this fault situation, the freewheeling diode can provide a conduction path so that the electric energy of the upper-stage charge-discharge circuit is still transmitted to the lower-stage charge-discharge circuit. The high voltage of the fault level can destroy the downstream charge-discharge circuit, so that the entire Marx generator 3 can maintain the normal operation of most of the charge-discharge circuits even if a single-stage charge-discharge circuit 3i fails, thereby improving the availability and utilization rate of the entire Marx generator 3. It is beneficial to improve the stability of the electrostatic precipitator 9.

[0084] In one embodiment, each stage of the charging and discharging circuit 3i also includes a second protection resistor 3i8; the second protection resistor 3i8 is connected in series with the freewheeling diode 3i7, and the second protection resistor 3i8 is connected to the anode of the freewheeling diode 3i7; the second protection resistor 3i8 is used to protect the freewheeling diode 3i7.

[0085] Here, the freewheeling diode 3i7 is located in the discharge loop, and when a fault occurs, the short-circuit high current impact is likely to damage the diode. The second protection resistor 3i8 is connected in series with the diode to play a role in current limiting protection, preventing the diode from being damaged by excessive current.

[0086] Since the second protection resistor 3i8 needs to withstand high voltage and high current, it can be a special high-voltage and high-power resistor such as a metal oxide film resistor, a ceramic resistor, or a carbon film resistor.

[0087] Figure 3 is a structural diagram of an inverter 2 according to an exemplary embodiment. In one embodiment, Figure 3As shown in the figure, the inverter 2 includes a PWM signal generator 21, a full-bridge ZVT-PWM circuit 22, and a boost isolation winding 23; the PWM signal generator 21, the full-bridge ZVT-PWM circuit 22, and the boost isolation winding 23 are connected in sequence; the full-bridge ZVT-PWM circuit 22 is connected to the rectifier 1; the boost isolation winding 23 is coupled to the charging isolation winding of the Marx generator 3; the full-bridge ZVT-PWM circuit 22 is used to achieve zero-voltage turn-on of the bridge arm switching tubes and zero-current turn-on of the body diodes in the full-bridge ZVT-PWM circuit 22, so as to reduce the losses of the bridge arm switching tubes and the body diodes.

[0088] The full-bridge ZVT-PWM circuit 22 includes a first inductor 225, a second inductor 227, a first switching tube 2211, a first diode 2212, a first capacitor 2213, a second switching tube 2221, a second diode 2222, a second capacitor 2223, a third switching tube 2231, a third diode 2232, a third capacitor 2233, a fourth switching tube 2241, a fourth diode 2242, a fourth capacitor 2243, and a fifth capacitor 226. Among them, the first switching tube 2211, the second switching tube 2221, the third switching tube 2231, and the fourth switching tube 2241 form a full-bridge structure.

[0089] Among them, the first switching tube 2211 and the second switching tube 2221 form a leading bridge arm, the third switching tube 2231 and the fourth switching tube 2241 form a lagging bridge arm, the first switching tube 2211 and the third switching tube 2231 form an upper bridge arm, and the second switching tube 2221 and the fourth switching tube 2241 form a lower bridge arm. Each of these four switching tubes is connected in parallel with a capacitor, namely the first capacitor 2213, the second capacitor 2223, the third capacitor 2233, and the fourth capacitor 2243, and is anti-parallel with a diode, namely the first diode 2212, the second diode 2222, the third diode 2232, and the fourth diode 2242. The four switching tubes can be IGBTs, and the four diodes can be fast-recovery diodes.

[0090] The first inductor 225 and the fifth capacitor 226 form an LC filter circuit, and the fifth capacitor 226 also serves as an input capacitor at the same time. The second inductor 227 is a resonant inductor, which is connected in series with the boost isolation winding 23 and is integrally connected between the output terminal of the first switching tube 2211 and the output terminal of the fourth switching tube 2241.

[0091] The PWM signal generator 21 is respectively connected to the control terminals of the first switching tube 2211, the second switching tube 2221, the third switching tube 2231, and the fourth switching tube 2241, and is used to control the on-off of the four switching tubes, so as to invert the direct current input by the rectifier 1 back into high-voltage alternating current. By phase-shift control of the four switching tubes, the output voltage can be adjusted.

[0092] Taking the first switching tube 2211 and the fourth switching tube 2241 as an example, at the time t0 - t1, the first switching tube 2211 and the fourth switching tube 2241 are turned on, the second switching tube 2221 and the third switching tube 2231 are turned off, the third capacitor 2233 and the fourth capacitor 2243 are charged, the current passing through the inductor in the circuit continuously increases, the voltage continuously decreases, the voltages of the two capacitors are the same and continuously rise, that is, the voltage across the third capacitor 2233 is equal to the voltage across the fourth capacitor 2243. At the time t1, the inductor voltage in the circuit drops to be the same as the voltages of the two capacitors, and the capacitor charging ends. At the time t1 - t2, the inductor voltage is less than the capacitor voltage, the third capacitor 2233 and the fourth capacitor 2243 start to discharge the circuit, the inductor current in the circuit continues to increase, and at this time an LC resonance circuit is formed, triggering the conduction of the second diode 2222 and the third diode 2232. In the stage of t2 - t3, the second diode 2222 and the third diode 2232 are conducting, the voltage across the second diode 2222 is equal to the voltage across the third diode 2232 and equal to zero, and at this time the second switching tube 2221 and the third switching tube 2231 are triggered, realizing the zero - voltage conduction of the switching tubes. By controlling the turn - on and turn - off of the four switching tubes, they are used as auxiliary switching tubes for each other. It is possible to achieve the zero - voltage conduction of the four switching tubes and the zero - current turn - off of the four diodes without increasing the voltage or current, so as to reduce the losses of the switching tubes and diodes.

[0093] The present disclosure also provides a high - voltage pulse power supply for electrostatic precipitation, including: a three - phase AC power supply 8 and a high - voltage pulse generator as described in any one of the above; the three - phase AC power supply 8 is connected to the rectifier 1 of the high - voltage pulse generator.

[0094] The present disclosure also provides an electrostatic precipitation system, including: a three - phase AC power supply 8, an electrostatic precipitator 9 and a high - voltage pulse generator as described in any one of the above; the three - phase AC power supply 8 is connected to the rectifier 1 of the high - voltage pulse generator; the Marx generator 3 of the high - voltage pulse generator is coupled to the electrostatic precipitator 9.

[0095] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above - mentioned embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0096] In addition, it should be noted that, in the various specific technical features described in the above - mentioned specific embodiments, they can be combined in any appropriate way without contradiction. To avoid unnecessary repetition, the present disclosure does not separately describe various possible combination methods.

[0097] In addition, any combination can be made among various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A high-voltage pulse generator for electrostatic precipitation, characterized in that, It includes a rectifier (1), an inverter (2), and a Marx generator (3); The rectifier (1) is connected to the inverter (2), and the inverter (2) is coupled to the Marx generator (3); The rectifier (1) is used to be connected to a three-phase AC power supply (8); The Marx generator (3) is used to be coupled to an electrostatic precipitator (9); The rectifier (1) is used to rectify the three-phase alternating current output by the three-phase AC power supply (8) into direct current and output the direct current to the inverter (2); The inverter (2) is used to invert the direct current into high-frequency alternating current and output the high-frequency alternating current to the Marx generator (3); The Marx generator (3) is used to convert the high-frequency alternating current into high-voltage pulses and output the high-voltage pulses to the electrostatic precipitator (9).

2. The high-voltage pulse generator according to claim 1, wherein The Marx generator (3) includes a trigger circuit (301), a multi-stage charge and discharge circuit, and a discharge isolation winding (302); The trigger circuit (301) is respectively connected to each stage of the charge and discharge circuit (3i); The multi-stage charge and discharge circuits are connected end to end in sequence; The primary charge and discharge circuit (31) and the final-stage charge and discharge circuit (3n) in the multi-stage charge and discharge circuit are respectively connected to both ends of the discharge isolation winding (302); The boost isolation winding (23) of the inverter (2) is respectively coupled to each stage of the charge and discharge circuit (3i); The discharge isolation winding (302) is used to be coupled to the electrostatic precipitator (9).

3. The high-voltage pulse generator according to claim 2, wherein Each stage of the charge and discharge circuit (3i) includes: A charge isolation winding (3i1), a first protection resistor (3i2), a charge capacitor (3i3), a discharge switch tube (3i4), and a discharge capacitor (3i5); The charge isolation winding (3i1), the charge capacitor (3i3), and the first protection resistor (3i2) are connected end to end in sequence to form a closed loop; The charge capacitor (3i3) is connected in parallel with the discharge capacitor (3i5); The discharge switch tube (3i4) is connected between the charge capacitor (3i3) and the discharge capacitor (3i5). The input end (3i41) of the discharge switch tube is connected to the charge capacitor (3i3), and the output end (3i42) of the discharge switch tube is coupled to the discharge capacitor (3i5); The discharge capacitor (3i5) is used to store the electric energy of the charge capacitor (3i3) when the discharge switch tube (3i4) is turned on and transfer the high-voltage pulse to the discharge isolation winding (302) to prevent the charge capacitor (3i3) from being damaged by the high-voltage pulse.

4. The high-voltage pulse generator according to claim 3, wherein The discharge capacitors of the primary charge and discharge circuit (31), the discharge capacitors of the remaining stages of the charge and discharge circuits, the discharge capacitor of the final-stage charge and discharge circuit (3n), and the discharge isolation winding (302) are connected in series in sequence and form a closed loop; The trigger circuit (301) is respectively connected to the control end (3i43) of the discharge switch tube of each stage of the charge and discharge circuit; The boost isolation winding (23) of the inverter (2) is respectively coupled to the charging isolation winding (3i1) of each stage of the charging and discharging circuit.

5. The high-voltage pulse generator according to claim 4, characterized in that, Each stage of the charging and discharging circuit (3i) further includes a filtering inductor (3i6); The filter inductor (3i6) is connected between the output end (3i42) of the discharge switch tube and the discharge capacitor (3i5); The filter inductor (3i6) is used for filtering to stabilize the voltage of the charging and discharging circuit.

6. The high-voltage pulse generator according to claim 4 or 5, characterized in that Each stage of the charging and discharging circuit (3i) further includes a freewheeling diode (3i7); The freewheeling diode (3i7) is connected in parallel with the charging capacitor (3i3), and the cathode of the freewheeling diode (3i7) is connected to the output end (3i42) of the discharge switch tube; The freewheeling diode (3i7) is used to maintain the conduction state between the previous-stage charge-discharge circuit and the next-stage charge-discharge circuit of the current-stage charge-discharge circuit when a fault occurs in the current-stage charge-discharge circuit.

7. The high-voltage pulse generator according to claim 6, wherein, Each stage of the charging and discharging circuit (3i) further includes a second protective resistor (3i8); The second protection resistor (3i8) is connected in series with the freewheeling diode (3i7), and the second protection resistor (3i8) is connected to the anode of the freewheeling diode (3i7); The second protection resistor (3i8) is used to protect the freewheeling diode (3i7).

8. The high-voltage pulse generator according to claim 7, characterized in that, The inverter (2) comprises a PWM signal generator (21), a full-bridge ZVT-PWM circuit (22) and a boost isolation winding (23); The PWM signal generator (21), the full-bridge ZVT-PWM circuit (22), and the boost isolation winding (23) are connected in sequence; The full-bridge ZVT-PWM circuit (22) is connected to the rectifier (1); The boost isolation winding (23) is coupled to the charging isolation winding (3i1) of the Marx generator (3); The full-bridge ZVT-PWM circuit (22) is used to achieve zero voltage conduction of a bridge arm switch tube and zero current conduction of a body diode in the full-bridge ZVT-PWM circuit (22), so as to reduce losses of the bridge arm switch tube and the body diode.

9. A high-voltage pulse power supply for electrostatic dust removal, characterized in that, include: A three-phase AC power supply (8) and a high-voltage pulse generator as claimed in any one of claims 1 to 8; The three-phase AC power source (8) is connected to the rectifier (1) of the high-voltage pulse generator.

10. An electrostatic dust removal system, characterized in that, include: A three-phase AC power supply (8), an electrostatic precipitator (9), and a high-voltage pulse generator as claimed in any one of claims 1 to 8; The three-phase AC power source (8) is connected to the rectifier (1) of the high-voltage pulse generator; The Marx generator (3) of the high-voltage pulse generator is coupled to the electrostatic precipitator (9).

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