A DC bus multiplication nanosecond pulse power supply and control method

Abstract

A DC bus multiplication nanosecond pulse power supply and control method, including an adjustable dual-isolated output DC power supply, a pulse generating circuit, a pulse boosting transformer with integrated core reset, a pulse rising edge control circuit with integrated core reset, and a pulse width and falling edge control circuit with integrated core reset. The adjustable dual-isolated output DC power supply is used to increase the pulse voltage DC voltage to match the voltage level of the semiconductor power module. The pulse generating circuit adopts a DC bus cascade multiplication scheme to achieve pulse voltage DC voltage multiplication, breaking through the limitation of the voltage level of the semiconductor power module itself, increasing the output voltage of the nanosecond pulse high-voltage power supply, reducing the number of coil turns of the pulse transformer and the magnetic switch, increasing the working range of the B-H curve of the magnetic core, achieving precise control of the pulse voltage DC voltage, reducing the cost of the equipment, and improving the reliability and application value of the equipment.

Description

Technical Field

[0001] The invention relates to the conversion of direct current or alternating current input power to surge output power and their control or regulation, and in particular to a direct current bus multiplication nanosecond pulse power supply and a control method thereof. Background Art

[0002] Nanosecond pulse high voltage power supply is a special high voltage power supply equipment. Nanosecond pulse high voltage can be used to generate high voltage pulse discharge, and has broad application prospects in the fields of air pollution control, water pollution control, material surface treatment, semiconductor material processing, etc. Nanosecond pulse high voltage discharge has many significant advantages. The time scale is short. The time scale of nanosecond pulse discharge is very short, and the processing time of each pulse is less than 1 microsecond. This high-speed processing method makes nanosecond pulse discharge have significant advantages in situations that require fast response and efficient processing. Rapid energy release. Nanosecond high voltage pulses can release extremely high energy in a very short time (nanosecond level), forming a high energy density electric field and plasma. The voltage waveform of nanosecond pulse discharge has steep rising and falling edges, which makes the discharge process faster and more efficient.

[0003] In nanosecond pulse high-voltage power supplies, the pulse generation circuit is usually driven and controlled by a semiconductor power module. With the development of semiconductor power module technology, the operating voltage and current of semiconductor power modules such as insulated gate bipolar transistors IGBT, silicon carbide metal oxide semiconductor field effect transistors Sic MOSFET, and integrated gate commutated thyristors IGCT have been significantly improved. Common voltage levels of semiconductor power modules are: 650V, 1200V, 1700V, 3300V, 4500V, 6500V, etc. Nanosecond pulse high-voltage power supplies are generally powered by three-phase industrial frequency mains voltage. After rectification, the DC bus voltage is generally only 500V~600V, which does not match the voltage level of the semiconductor power module. Increasing and adjusting the DC bus voltage can achieve matching with various levels of semiconductor power modules and improve the performance of nanosecond pulse high-voltage power supplies.

[0004] In the field of nanosecond pulse high voltage power supply, the existing technical solutions are as follows:

[0005] Chinese invention patent CN116707319A discloses a pulse power supply and control method for suppressing bus voltage fluctuations. A dual-active full-bridge converter is connected to the DC bus through an LC circuit; a primary-side sampling module and a secondary-side sampling module are respectively connected to the dual-active full-bridge converter and a control unit; the control unit is connected to a pulse generation module; the pulse generation module outputs a control signal to control the switch tube of the dual-active full-bridge converter; the pulse power identification module of the control unit is connected to the delay module through a pulse power adjustment module, and the pulse power identification module is also connected to the delay module through an estimation prediction module. The pulse power adjustment module includes a power change calculation module and a shift ratio calculation module, and the estimation prediction module includes an adaptive step size generation module, a capacitor voltage prediction module and a cost function evaluation module. The present invention can effectively suppress the oscillation of the DC bus voltage, while quickly responding to changes in the pulse power load to ensure the high quality of the output voltage.

[0006] Chinese invention patent CN117254704A discloses a frequency division analog resistance control method for grid-connected voltage-type rectifiers under unbalanced power grids. First, the grid current signal and DC bus voltage signal are obtained in a two-phase stationary coordinate system. Secondly, according to the idea of ​​frequency division control, the DC component and the double frequency component of the DC bus voltage are extracted based on a notch filter and a bandpass filter respectively. Then, a DC voltage control loop is designed to regulate the DC component of the DC bus voltage, and a pulsating voltage control loop is designed to suppress the double frequency component of the DC bus voltage caused by the unbalanced power grid. Finally, based on the idea of ​​analog resistance control, the output of the two-way voltage controller and the sampled grid current signal are used to calculate and filter through a bandpass filter to obtain the voltage reference on the AC side of the rectifier, and then a pulse signal for controlling the conduction of the rectifier switch tube is generated according to the carrier modulation method. This method is completely implemented in a stationary coordinate system, without the need for precise line parameters, grid voltage sensors, and complex phase-locked loop algorithms.

[0007] The performance of nanosecond pulse high-voltage power supply is also affected by the pulse power supply magnetic core and magnetic switch magnetic core. Improving the magnetic core will help improve the performance of nanosecond pulse high-voltage power supply.

[0008] At the same time, in pollution control applications, most pollutants are highly corrosive. Reactors used with nanosecond power supplies are usually made of high-performance stainless steel, and some even require duplex stainless steel. Therefore, the cost of the reactor is very high, which limits its application. By improving the performance of nanosecond pulsed high-voltage power supplies and increasing the output voltage of the pulse power supply, it is helpful to increase the discharge distance of the reactor, reduce the cost of the reactor, and improve the application value.

[0009] If a voltage level semiconductor power module is selected, that is, the maximum working DC bus voltage is determined, in order to increase the output of the pulse high voltage power supply and reduce the cost of the reactor, the typical method is to increase the pulse transformer ratio N, but the method of increasing the pulse transformer ratio will cause the equivalent capacitance value of the reactor to change. The converted equivalent capacitance value of the reactor is the square of the ratio. 2 The capacitance value of C is very large, and the leakage inductance of the pulse transformer will also increase with the increase of the transformation ratio, which will affect the rising edge and pulse width of the pulse, resulting in changes in the power supply characteristics and poor environmental protection application management effects. Therefore, technicians studying nanosecond pulse high voltage electricity hope to break through the voltage level of semiconductor power modules, further increase the maximum working DC bus voltage, and improve the performance of nanosecond pulse high voltage power supplies. Summary of the invention

[0010] In view of the problems described in the background technology, the present invention proposes a technical solution of a DC bus multiplied nanosecond pulse power supply and a control method, and the specific technical solution is as follows:

[0011] A DC bus multiplication nanosecond pulse power supply comprises a three-phase rectifier filter with an integrated buffer circuit, an adjustable dual-isolated output DC power supply, a dual pulse generating circuit, a pulse boosting transformer with integrated magnetic core reset, a pulse energy storage circuit, a pulse rising edge control circuit with integrated magnetic core reset, and a pulse width and falling edge control circuit with integrated magnetic core reset. The invention is characterized in that: the adjustable dual-isolated output DC power supply controls and improves the matching of the pulse DC voltage and the voltage level of the semiconductor power module; the DC bus cascade multiplication of the dual pulse generating circuit doubles the pulse DC voltage; the working range of the BH curve of the magnetic core is improved by the pulse boosting transformer with integrated magnetic core reset, the pulse rising edge control circuit with integrated magnetic core reset, and the pulse width and falling edge control circuit with integrated magnetic core reset.

[0012] Control the working current of the two groups of filter capacitors in the double pulse generation circuit and the working current of the two semiconductor power modules so that the requirements of the maximum average current value allowed for continuous operation and the maximum pulse current value allowed for continuous operation are met at the same time, and the two control operation formulas are established at the same time:

[0013]

[0014]

[0015] Where: I VA The maximum average current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I VP The maximum pulse current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I CAThe maximum average current value allowed for continuous operation of the two groups of filter capacitors; I CP The maximum current value allowed for two groups of filter capacitors to work continuously; U DCa , U DCb The two rated voltage values ​​of the adjustable dual isolated output DC power supply; C P1 is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; N is the transformation ratio of the pulse boost transformer; L S is the leakage inductance of the pulse boost transformer; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generation circuit;

[0016] The adjustable dual-isolated output DC power supply improves the DC voltage after rectification of the three-phase industrial frequency power grid. The dual pulse generating circuit provides two adjustable isolated and independently output DC power supplies. The transformation ratio of the dual-output high-frequency isolation transformer is matched with the voltage level of the semiconductor power module in the dual pulse generating circuit. At the same time, it is used for cascading during the operation of the dual pulse generating circuit to achieve doubling of the DC bus of the pulse power supply.

[0017] Furthermore, the total output power P of the adjustable dual-isolated output DC power supply is DC The regulation control meets the following formula conditions:

[0018]

[0019] P DC is the total output power of the adjustable dual isolated output DC power supply; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

[0020] Further, as a preferred embodiment of the present invention, the reset circuit of the pulse boost transformer with integrated magnetic core reset is isolated from the power grid with an isolation transformer, which can improve the anti-interference ability and adopt DC power supply. The higher the pulse repetition frequency, the higher the reset voltage. The reset voltage U1 of the magnetic core of the pulse boost transformer is adjusted and controlled. reset Satisfies the following formula:

[0021]

[0022] U1reset is the reset voltage of the pulse boost transformer core, N1 is the number of turns of the pulse boost transformer reset coil, △B1 is the difference between the magnetic flux density of the pulse boost transformer core -Bm and +Bm, S1 is the cross-section of the pulse boost transformer core, and Ts is the cycle time corresponding to the maximum repetition frequency of the double pulse generating circuit.

[0023] The operating currents of the two groups of filter capacitors in the control double pulse generating circuit and the operating currents of the two semiconductor power modules are optimized to the following two formulas for the convenience of automatic control program operation:

[0024]

[0025]

[0026] Where: I VA The maximum average current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I VP The maximum pulse current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I CA The maximum average current value allowed for continuous operation of the two groups of filter capacitors; I CP The maximum current value allowed for two groups of filter capacitors to work continuously; U DCa , U DCb The two rated voltage values ​​of the adjustable dual isolated output DC power supply; C P1 is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; N is the transformation ratio of the pulse boost transformer; L S is the leakage inductance of the pulse boost transformer; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

[0027] Further, as a preferred embodiment of the present invention, the equivalent series resistance ESR of the filter capacitor in the DC bus multiplier nanosecond pulse power supply circuit is less than 60 μΩ, and the resistance specification of the equivalent series resistance is calculated using the following formula:

[0028] ESR = tanδ / (2π×f×C)

[0029] Where: tanδ represents the loss tangent, f is the pulse operating frequency, and C is the capacitor capacitance.

[0030] The pulse boost transformer for integrated magnetic core reset, the pulse rising edge control circuit for integrated magnetic core reset and the pulse width and falling edge control circuit for integrated magnetic core reset are used to improve the working range of the magnetic core in the BH curve.

[0031] The filter capacitor of the adjustable dual-isolated output DC power supply has the following functions: a. DC filtering for high-frequency rectification, b. voltage balancing of the two loops of the dual-pulse generating circuit, c. energy storage capacitor of the pulse generator, d. recovery of residual energy of resonance between the pulse boost transformer and the pulse energy storage circuit; two groups of filter capacitors C of the adjustable dual-isolated output DC power supply DCa , C DCb The capacitance value is equal, the capacitance error is less than ±1%, and the capacitance value is Choose between: C P1 is the capacitance of the energy storage capacitor connected to the secondary side of the pulse boost transformer, and N is the transformation ratio of the pulse boost transformer.

[0032] The adjustable dual-isolated output DC power supply is provided with a DC power supply by a three-phase rectifier filter with an integrated buffer circuit, including V11, V12, V13, V14 semiconductor power modules forming an H-bridge inverter, a resonant capacitor C11, a resonant inductor L11, a dual-output high-frequency isolation transformer TR1, two independent high-frequency rectifier bridges ZD1, ZD2 and filter capacitors C21, C22; V11, V12, V13, V14 semiconductor power modules form the input PWM drive of the H-bridge inverter, and changing the PWM drive can control the size of the DC power supply output voltage.

[0033] Compared with the prior art, the beneficial technical effects of the present invention are

[0034] 1. A DC bus multiplication nanosecond pulse power supply and control method improves the pulse DC voltage through an adjustable dual-isolated output DC power supply to achieve matching with the voltage level of the semiconductor power module. At the same time, the DC bus cascade multiplication scheme of the dual pulse generating circuit is used to achieve pulse voltage DC voltage multiplication. The dual pulse generating circuit breaks through the voltage level of the semiconductor power module itself and achieves voltage level doubling application. Without increasing the transformation ratio of the pulse boosting transformer, the output voltage of the pulse high-voltage power supply is greatly increased, the performance of the nanosecond pulse high-voltage power supply is improved, and a high multiplication of the pulse voltage DC voltage is achieved, breaking through the limitations of traditional technologies.

[0035] 2. A DC bus multiplied nanosecond pulse power supply and control method improves the working range of the BH curve of the core, reduces the number of coil turns of the pulse boost transformer and the magnetic switch, improves the performance of the nanosecond pulse high-voltage power supply, and reduces the cost of the nanosecond pulse high-voltage power supply through an integrated core reset pulse boost transformer, an integrated core reset pulse rising edge control circuit, and an integrated core reset pulse width and falling edge control circuit.

[0036] 3. A DC bus multiplier nanosecond pulse power supply and control method improves the performance of the nanosecond pulse high-voltage power supply, increases the output voltage of the nanosecond pulse high-voltage power supply, amplifies the discharge distance of the reactor, reduces the cost of the reactor, improves the application value of the nanosecond pulse high-voltage power supply, and expands the application scope of the equipment.

[0037] 4. A DC bus multiplied nanosecond pulse power supply and control method, which reduces the number of coil turns of the pulse boost transformer and the magnetic switch, reduces the size and weight of the equipment, reduces the cost of the equipment, and improves the cost performance of the equipment through an integrated core reset pulse boost transformer, an integrated core reset pulse rising edge control circuit, and an integrated core reset pulse width and falling edge control circuit.

[0038] 5. A DC bus multiplied nanosecond pulse power supply and control method, which improves the working range of the BH curve of the core and improves the efficiency and stability of the equipment through an integrated core reset pulse boost transformer, an integrated core reset pulse rising edge control circuit and an integrated core reset pulse width and falling edge control circuit.

[0039] 6. A DC bus multiplication nanosecond pulse power supply and control method, through an adjustable dual-isolated output DC power supply and a DC bus cascade multiplication scheme of a dual pulse generating circuit, achieves precise control of the pulse voltage DC voltage, and improves the accuracy and reliability of the equipment.

[0040] 7. A DC bus multiplier nanosecond pulse power supply and control method improves the reliability of the equipment and reduces the failure rate of the equipment by increasing the working range of the BH curve of the magnetic core and reducing the number of coil turns of the pulse boost transformer and the magnetic switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The invention discloses a schematic diagram of a direct current bus multiplied nanosecond pulse power supply and a control method.

[0042] Figure 2 The present invention is a charging waveform diagram of a three-phase rectifier filter with an integrated buffer circuit in a DC bus multiplied nanosecond pulse power supply and control method, wherein: K2 and K1 represent the switch state, 0 represents OFF, and 1 represents ON.

[0043] Figure 3 The invention discloses a simplified schematic diagram of the equivalent bus cascade multiplication mode in a DC bus multiplication nanosecond pulse power supply and a control method.

[0044] Figure 4 The present invention is a simplified schematic diagram of the equivalent non-bus cascade multiplication mode in a DC bus multiplication nanosecond pulse power supply and control method, wherein the × on the switch indicates disconnection.

[0045] Figure 5 It is a bus cascade multiplication mode in a DC bus multiplication nanosecond pulse power supply and control method. When a single bus is multiplied from 950V to 1900V, the nanosecond pulse power supply waveform is shown, where: 201 is the switch state of PWM1 driving access control point 21 and PWM2 driving access control point 22, 21=ON, 22=OFF or 21=OFF, 22=ON; 202 is a schematic diagram of the DC voltage DC1, DC2 and the pulse boost transformer TR2 voltage reset by the integrated magnetic core; I1 is the current.

[0046] Figure 6 It is a non-bus cascade multiplication mode in a DC bus multiplication nanosecond pulse power supply and control method, a single bus 950V, a nanosecond pulse power supply waveform diagram when a single pulse generator is working, wherein: 203 is the switch state of PWM1 drive access control point 21 and PWM2 drive access control point 22, 21=ON, 22=OFF or 21=OFF, 22=ON; 204 is a schematic diagram of DC voltages DC1, DC2 and the pulse boost transformer TR2 voltage reset by the integrated magnetic core; I1 is the current.

[0047] Figure 7 The invention discloses a core BH curve of a DC bus multiplied nanosecond pulse power supply and a control method.

[0048] Figure 8 The invention discloses a pulse boost transformer core reset circuit and a magnetic switch core reset circuit in a direct current bus multiplication nanosecond pulse power supply and a control method.

[0049] Fig. 9 The invention relates to a 50mm diameter reactor and a 100mm diameter reactor in a DC bus multiplication nanosecond pulse power supply and a control method, wherein: 50 is a 50mm diameter reactor, and 100 is a 100mm diameter reactor.

[0050] In the attached figure: DC1 is a DC voltage, V21 is a semiconductor power module, V22 is a semiconductor power module, 21 is a PWM1 drive access control point, 22 is a PWM2 drive access control point, V11, V12, V13, V14 are semiconductor power modules forming an H-bridge inverter, C11 is a resonant capacitor, L11 is a resonant inductor, TR1 is a dual-output high-frequency isolation transformer, ZD1 and ZD2 are two independent high-frequency rectifier bridges, C21 and C22 are filter capacitors, 11, 12, 13, and 14 are PWM drive input points of the H-bridge inverter composed of V11, V12, V13, and V14 semiconductor power modules, V1, V2, and V3 are power thyristors, MZ1 is a rising edge control magnetic switch, MZ2 is a pulse falling edge magnetic switch, DCa and DCb are capacitors, TR2 is a pulse boost transformer with integrated core reset, P1 and P2 are voltage measurement points. DETAILED DESCRIPTION

[0051] The DC bus multiplied peak adjustable nanosecond pulse power supply is powered by a three-phase industrial frequency AC power supply. It is mainly composed of a three-phase rectifier filter with integrated buffer circuit, an adjustable dual-isolated output DC power supply, a dual pulse generating circuit, a pulse boosting transformer with integrated core reset, a pulse energy storage circuit, a pulse rising edge control circuit with integrated core reset, and a pulse width and falling edge control circuit with integrated core reset.

[0052] The three-phase rectifier filter with integrated buffer circuit comprises a three-phase rectifier circuit composed of power diodes and power thyristors, a buffer circuit, a filter capacitor, a control circuit of the buffer circuit, and a control circuit of the three-phase rectifier circuit.

[0053] The adjustable dual-isolated output DC power supply is provided by the three-phase rectifier filter of the front-stage integrated buffer circuit. The circuit includes an H-bridge inverter, a resonant capacitor, a resonant inductor, a dual-output high-frequency isolation transformer, and two independent high-frequency rectifier and filter capacitors. The adjustable dual-isolated output DC power supply mainly provides two mutually isolated and independently output DC power supplies for the subsequent dual-pulse generation circuit. By designing the appropriate transformation ratio of the dual-output high-frequency isolation transformer, the voltage level of the semiconductor power module in the dual-pulse generation circuit can be matched. At the same time, during the operation of the nanosecond pulse power supply, the operating frequency of the H-bridge inverter can be adjusted in real time to control and change the output peak voltage of the nanosecond pulse power supply.

[0054] The total output power P of the adjustable dual isolated output DC power supply DC Should meet:

[0055]

[0056] P DCis the total output power of the adjustable dual isolated output DC power supply; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generation circuit;

[0057] The dual-output high-frequency isolation transformer of the adjustable dual-isolated output DC power supply consists of a primary coil, a high-frequency transformer core, and a secondary coil. The primary coil is a single coil, and the secondary coil has two coils with the same number of turns to ensure that the output high-frequency AC voltage is equal. The high-frequency transformer ratio is designed according to the maximum output DC voltage, and the maximum output DC voltage is 0.5~0.6 times the maximum reverse voltage that the semiconductor power module can withstand. The isolation withstand voltage between the primary coil of the high-frequency transformer, the high-frequency transformer core, and the secondary coil is designed according to the cascade multiplication busbar design, which is greater than or equal to 4 times the maximum reverse voltage that the semiconductor power module can withstand. Assuming that a 1700V IGBT module semi-conducting module is selected, the maximum output DC voltage is 850V~1020V, and the isolation withstand voltage between the primary coil of the high-frequency transformer, the high-frequency transformer core, and the secondary coil is 6800V.

[0058] The filter capacitor of the adjustable dual-isolated output DC power supply has multiple circuit functions. The first function is the DC filtering of high-frequency rectification, the second function is the voltage equalization of the two loops of the dual pulse generating circuit, the third function is the energy storage capacitor of the pulse generator, and the fourth function is the recovery of the residual energy of the resonance between the pulse boost transformer and the pulse energy storage circuit.

[0059] The filter capacitor should meet the requirements of multiple circuit function parameters of DC filtering and pulse generator at the same time. DCa , C DCb The capacitance value is equal, and the capacitance error should be less than ±1%, which meets the voltage equalization requirement of the dual pulse generation circuit. The capacitance value of the filter capacitor needs to meet the requirements of the DC filter of the high-frequency rectification and the requirements of the pulse generator. The filter capacitor C DCa , C DCb The capacitance value of the capacitor is Choose between C P1 The capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer. DCa , C DCb If the capacitance is too small, the peak value of the pulse boost transformer will fluctuate, affecting the control accuracy. If the capacitance is too large, the cost will be too high. DCa , C DCb The rated voltage is greater than or equal to the maximum reverse voltage that the semiconductor power module of the pulse generator can withstand.

[0060] The double pulse generating circuit is powered by an adjustable dual isolated output DC power supply. The filter capacitor C of the DC power supply DCb DCb The positive end of the semiconductor power module 2 is connected to one end of the semiconductor power module 2, and the other end of the semiconductor power module 2 is connected to the filter capacitor C of the DC power supply DCa. DCa The negative polarity end of the DC power supply DCa filter capacitor C DCa The positive end of the semiconductor power module 1 is connected to one end of the semiconductor power module 1, and the other end of the semiconductor power module 1 is connected to one end of the primary coil of the pulse boost transformer, and the other end of the primary coil of the pulse boost transformer is connected to the filter capacitor C of the DC power supply DCb. DCb The negative polarity end of the 200V DC bus forms a DC bus cascade double pulse generation circuit system. The equivalent circuit is as follows: Figure 3 As shown in the figure, the leakage inductance of the transformer is hidden in the transformer coil. A diode is also connected in parallel to each loop of the double pulse generation circuit to provide protection after a semiconductor power module in the double pulse generation circuit fails.

[0061] The semiconductor power module 1 and the semiconductor power module 2 of the double pulse generating circuit are driven and controlled by PWM1 and PWM2. The width Pw of PWM1 and PWM2 is the same, which is related to the leakage inductance Ls of the pulse boosting transformer, the transformation ratio N of the pulse boosting transformer, and the capacitance Ca of the pulse energy storage circuit. The driving width Pw is greater than or equal to half of the resonant period of the product of the leakage inductance Ls of the pulse boosting transformer, the square of the transformation ratio of the pulse boosting transformer and the capacitance Ca of the pulse energy storage circuit, that is, When the semiconductor power module 1 and the semiconductor power module 2 of the double pulse generation circuit work in the bus cascade multiplication mode, the equivalent circuit schematic diagram is as follows: Figure 3 As shown, PWM1 and PWM2 drivers must be completely synchronized. The rising and falling edge change time errors of PWM1 and PWM2 drive waveforms must be controlled within 20ns, forming a bus cascade multiplication, and the pulse power supply output peak voltage is doubled. The output waveform is as follows Figure 5 The semiconductor power module 1 and the semiconductor power module 2 of the double pulse generation circuit can also work in the non-busbar cascade multiplication mode. The equivalent circuit schematic diagram is shown in FIG. Figure 4 As shown, there is only one drive output and the other is completely closed. When PWM1 drive or PWM2 drive output is in non-bus cascade multiplication mode, the pulse power supply output peak voltage is only half of the bus cascade multiplication mode. The output waveform is as follows Figure 6 The non-busbar cascade multiplication mode can be applied to situations where the load needs to run at a lower voltage under certain working conditions, and when one of the semiconductor power modules 1 fails to drive, so that the pulse power supply can retain a certain pulse voltage output capacity before shutting down for maintenance.

[0062] A reverse diode is connected in parallel next to the semiconductor power module 1 and the semiconductor power module 2 of the double pulse generating circuit. After the switch in the semiconductor power module 1 and the semiconductor power module 2 is disconnected, the reverse pulse current of the pulse generator is recharged through the reverse diode and flows back into the filter capacitor of the pulse power supply.

[0063] The dual pulse generating circuit can only be used for unipolar pulse power supply output, positive or negative output. The change of the positive and negative polarity of the pulse power supply output only requires changing the two connection points of the primary coil of the pulse boost transformer. Exchanging them will cause the change of the positive and negative polarity of the pulse power supply output.

[0064] Control the working current of the two groups of filter capacitors in the double pulse generation circuit and the working current of the two semiconductor power modules so that the requirements of the maximum average current value allowed for continuous operation and the maximum pulse current value allowed for continuous operation are met at the same time, and the two control operation formulas are established at the same time:

[0065]

[0066]

[0067] In order to facilitate the program operation of automatic control, the control operation formula is further optimized as follows:

[0068]

[0069]

[0070] Where: I VA The maximum average current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I VP The maximum pulse current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I CA The maximum average current value allowed for continuous operation of the two groups of filter capacitors; I CP The maximum current value allowed for two groups of filter capacitors to work continuously; U DCa , U DCb The two rated voltage values ​​of the adjustable dual isolated output DC power supply; C P1 is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; N is the transformation ratio of the pulse boost transformer; L S is the leakage inductance of the pulse boost transformer; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

[0071] Because the pulse current working current is very large when the pulse power supply is running, the equivalent series resistance (ESR) of the filter capacitor should be less than 60μΩ, otherwise the temperature rise will be too high, which will directly lead to damage to the filter capacitor.

[0072] ESR = tanδ / (2π×f×C)

[0073] Where: Where: tanδ represents the loss tangent, which is equal to the ratio of the active power to the reactive power of the dielectric; f is the pulse operating frequency; C is the capacitance value of the capacitor.

[0074] The pulse boost transformer with integrated core reset, the primary coil of the pulse boost transformer is connected to the dual pulse generating circuit, and the secondary coil of the pulse boost transformer is connected to the pulse energy storage circuit. The low voltage pulse passes through the primary coil of the pulse boost transformer, coupled through the magnetic core of the pulse boost transformer, and the secondary coil of the pulse boost transformer outputs a high voltage pulse. Since the dual pulse generating circuit can only be used for unipolar pulse power output, the transformer magnetic core works in the same quadrant of the BH curve, and the magnetic core BH curve is as follows Figure 8 As shown, the core is biased, the working range is between -Br~-Bm or between +Br~+Bm, the core working range is narrow, it is easy to saturate, and cause failure. The pulse boost transformer is equipped with an independent reset coil at the primary and connected to the core reset circuit. Assuming that the pulse power supply outputs positive polarity, after a pulse output ends, the core is in the +Br~+Bm interval of the core BH curve, and the core reset circuit is reversely reset to reset the core to the -Br~-Bm interval of the core BH curve. When the next pulse is output, the core BH curve can be used from the -Br~-Bm interval to the +Br~+Bm interval, which greatly provides the utilization rate of the pulse boost transformer core. At the same time, the increase in △B can greatly reduce the number of turns of the pulse boost transformer coil, control the leakage inductance of the pulse boost transformer, and improve the performance of the pulse boost transformer. The pulse power supply outputs negative polarity, the core interval is opposite, and the principle is the same as the positive polarity output of the pulse power supply. The pulse boost transformer has an independent reset coil on the primary side. Since the output of the pulse boost transformer is a high-voltage pulse, when the pulse boost transformer outputs a high-voltage pulse, the reset coil will also generate a pulse voltage through the magnetic core coupling. In order to reduce the induced voltage of the pulse on the reset coil and simplify the winding process of the reset coil, the independent reset coil on the primary side of the pulse boost transformer is designed to be 1 turn. The insulation withstand voltage of the reset coil of the pulse boost transformer is greater than the maximum peak voltage value of the secondary output of the pulse boost transformer, and greater than the effective voltage value of the secondary output of the pulse boost transformer at the maximum peak voltage and maximum operating frequency. The reset circuit of the pulse boost transformer is isolated from the power grid with an isolation transformer to improve anti-interference capabilities. It uses DC power supply. The higher the pulse repetition frequency, the higher the reset voltage. The reset voltage U1 of the magnetic core of the pulse boost transformer reset The following formula should be satisfied:

[0075]

[0076] U1reset is the reset voltage of the pulse boost transformer core, N1 is the number of turns of the pulse boost transformer reset coil, △B1 is the difference between the magnetic flux density of the pulse boost transformer core -Bm and +Bm, S1 is the cross-section of the pulse boost transformer core, and Ts is the cycle time corresponding to the maximum repetition frequency of the double pulse generating circuit.

[0077] Reset voltage U1 of the pulse boost transformer core reset After confirmation, set the current limiting resistor to determine the core reset current. The pulse boost transformer core reset current I1 determined by the current limiting resistor reset The following formula should be satisfied:

[0078]

[0079] N1 is the number of turns of the reset coil of the pulse boost transformer, Hm1 is the magnetic field intensity corresponding to the BH curve -Bm or +Bm of the pulse boost transformer core, and L1 is the magnetic path length of the pulse boost transformer core.

[0080] The pulse energy storage circuit is mainly composed of one or more capacitors connected in series, which is used to store the charge of the pulse current. When the load is a capacitive load, the capacitance of the pulse energy storage circuit is greater than or equal to the load capacitance value.

[0081] The pulse rising edge control circuit of integrated magnetic core reset is mainly composed of magnetic switch. The rising edge control magnetic switch coil turns N, the magnetic switch core cross-sectional area S, and the magnetic density △Bm of the magnetic switch core. The rising edge control magnetic switch parameters are related to the voltage Uc on the pulse energy storage circuit capacitor Ca. The time Tmax when the voltage Uc on the pulse energy storage circuit capacitor Cp rises to the maximum peak voltage UcMax is equal to Therefore, the product of the number of turns N of the magnetic switch, the cross-sectional area S of the magnetic core, and the magnetic flux density △Bm of the magnetic core should be greater than or equal to The voltage Uc on the capacitor Ca of the pulse energy storage circuit, the duration Tc of the voltage Uc, and the parameters of the rising edge control magnetic switch:

[0082]

[0083] That is, when the volt-second product of the voltage Uc of the pulse energy storage circuit capacitor and the duration Tc of the voltage Uc exceeds the product of the number of turns N of the magnetic switch, the cross-sectional area S of the magnetic core, and the magnetic density △Bm of the magnetic core, the rising edge controls the magnetic switch to saturate and conduct, and quickly supplies power to the load. The saturated inductance of the magnetic switch can adjust the pulse rising edge.

[0084] The pulse width and falling edge control circuit of the integrated magnetic core reset is mainly composed of a magnetic switch and a discharge resistor. The voltage Up on the load, the duration of the voltage Up on the load Tp. The number of turns of the width control magnetic switch coil is N, the cross-sectional area of ​​the magnetic switch core is S, and the magnetic density of the magnetic switch core is △Bm. The parameters of the width control magnetic switch should meet the following requirements:

[0085]

[0086] That is, when the volt-second product of the load voltage Up and the duration of the voltage Up is greater than the product of the number of turns N of the width control magnetic switch, the core cross-sectional area S, and the core magnetic density △Bm, the width control magnetic switch is saturated and turned on, and the electric energy stored in the load is released through the saturated inductance and discharge resistance of the magnetic switch, and quickly drops to zero, realizing pulse width control. The saturated inductance and discharge resistance of the magnetic switch can adjust the falling edge of the pulse.

[0087] Since the dual pulse generating circuit can only be used for unipolar pulse power supply output, the magnetic core of the pulse rising edge control magnetic switch and the pulse falling edge magnetic switch also work in the same quadrant of the BH curve. The BH curve of the magnetic core is as follows: Figure 8 As shown, the core is biased, the core BH curve in the working range is between -Br and -Bm or the working range is between +Br and +Bm, the core working range is narrow, resulting in a small value of the core magnetic flux density △Bm. In the formula, the value of the magnetic core magnetic density △Bm is small, and the number of turns of the magnetic switch coil N needs to be increased. The increase in the number of turns of the magnetic switch coil will increase the inductance after the magnetic switch is saturated, resulting in a sharp drop in the performance of the magnetic switch. The reset coils set for the pulse rising edge control magnetic switch and the pulse falling edge magnetic switch are respectively set. Since the interval between the pulse rising edge and the pulse falling edge is the pulse width time, which is less than 1us, the reset coil of the pulse rising edge control magnetic switch is connected in series with the reset coil of the pulse falling edge magnetic switch, and share a magnetic core reset circuit. Assuming that the pulse power supply is positively output, after a pulse output ends, the magnetic switch core is in the +Br~+Bm interval of the magnetic core BH curve, and the magnetic core reset circuit reversely resets the magnetic core to reset the magnetic core to the -Br~-Bm interval of the magnetic core BH curve. When the next pulse is output, the magnetic core BH curve can be used from the -Br~-Bm interval to the +Br~+Bm interval, which greatly increases the value of the magnetic switch △Bm, can greatly reduce the number of turns of the magnetic switch coil, reduce the inductance after the magnetic switch is saturated, and improve the performance of the magnetic switch. When the pulse power supply outputs negative polarity, the magnetic switch core interval is opposite, and the principle is the same as the positive polarity output of the pulse power supply. The reset coil of the magnetic switch, because the magnetic switch operates in a high-voltage pulse state, before the magnetic switch is saturated, the reset coil will also generate a pulse voltage through the magnetic core coupling. In order to reduce the induced voltage of the pulse on the reset coil and simplify the winding process of the reset coil, the reset coil of the magnetic switch is designed to be 1 turn. The insulation withstand voltage of the reset coil of the magnetic switch is greater than the maximum peak voltage value of the magnetic switch, and at the same time is greater than the effective voltage value of the magnetic switch operating at the maximum peak voltage and maximum operating frequency. The reset circuit of the magnetic switch is isolated from the power grid with an isolation transformer, which can improve the anti-interference ability. It uses DC power supply. The higher the pulse repetition frequency, the higher the reset voltage, and the reset voltage U2 of the magnetic switch core. reset The following formula should be satisfied:

[0088]

[0089] N2 is the number of turns of the magnetic switch reset coil, △B2 is the difference between the magnetic flux density of the magnetic switch core -Bm and +Bm, S2 is the cross-section of the rising edge control magnetic switch, S3 is the cross-section of the rising edge control magnetic switch, and Ts is the cycle time corresponding to the maximum repetition frequency of the double pulse generating circuit.

[0090] Reset voltage U2 of magnetic switch core reset After confirmation, set the current limiting resistor to determine the core reset current. The current limiting resistor determines the magnetic switch core reset current I2 reset The following formula should be satisfied:

[0091]

[0092] N2 is the number of turns of the magnetic switch reset coil, Hm2 is the magnetic field strength corresponding to the BH curve -Bm or +Bm of the magnetic switch core, L2 is the magnetic path length of the magnetic switch core. When two or more magnetic switches are reset in series, the core with the longest magnetic path is used.

[0093] A specific embodiment: a DC bus multiplier peak adjustable nanosecond pulse power supply, see Figure 1 .

[0094] The three-phase rectifier filter with integrated buffer circuit mainly provides DC power for the adjustable dual-isolated output DC power supply. At the same time, the integrated buffer circuit can pre-fill the filter capacitor of the three-phase rectifier filter before the pulse power supply works to reduce the high current impact on the three-phase power frequency power supply. In the specific circuit, the three-phase power frequency AC power supply AC1 is connected to the three-phase rectifier circuit composed of power diodes D1, D2, D3 and power thyristors V1, V2, V3. The capacitor C1 is filtered after the power frequency AC is rectified to output a stable DC power. The control circuit of the three-phase rectifier circuit, the power thyristors V1, V2, V3 are triggered by the trigger control circuit composed of relay K1, current limiting resistors Ra, Rb, Rc, and small current diodes Da, Db, Dc. The conduction and disconnection of the three-phase rectifier circuit are controlled by the conduction or disconnection of relay K1. The buffer circuit is composed of a small current diode D4, power diodes D2, D3, current limiting resistor R1, and relay K2. The conduction and disconnection of the buffer circuit are controlled by the conduction or disconnection of relay K2. Before the power supply works, the control point 2 controls the relay K2 to be energized, and the buffer circuit charges the capacitor C1. After the capacitor C1 voltage is charged high, the control point 1 controls the relay K1 to be energized again to reduce the large current impact of the zero voltage charging of the capacitor C1 on the three-phase power frequency power supply. After the control relay K1 is energized, the power thyristors V1, V2, and V3 are turned on after receiving the trigger signal, the power three-phase rectifier circuit works, the buffer circuit is bypassed by the power three-phase rectifier circuit, and the buffer circuit ends its work.

[0095] Three-phase rectifier filter with integrated buffer circuit, charging process see Figure 2 , control point 2 controls relay K2 to close, and the DC voltage DC1 starts to rise. After a delay of 2 to 4 seconds, the DC voltage DC1 rises to a level close to the normal working voltage. Control point 1 controls relay K1 to close, and the DC voltage DC1 rises to the normal working voltage.

[0096] The adjustable dual-isolated output DC power supply is mainly used to increase the DC voltage after rectification of the three-phase power frequency grid, and provide two adjustable isolated independent output DC power supplies for the dual pulse generation circuit. By designing the appropriate transformation ratio of the dual-output high-frequency isolation transformer, the voltage level of the semiconductor power module in the dual pulse generation circuit can be matched. At the same time, it is used for cascading in the operation of the dual pulse generation circuit to achieve the doubling of the pulse power supply DC bus. During the operation of the nanosecond pulse power supply, the operating frequency of the H-bridge inverter can be adjusted in real time, the voltage of the dual-isolated output DC power supply can be changed, and the output peak voltage of the nanosecond pulse power supply can be controlled. The adjustable dual-isolated output DC power supply is provided with a DC power supply by a three-phase rectifier filter with an integrated buffer circuit. The specific circuit includes an H-bridge inverter composed of V11, V12, V13, and V14 semiconductor power modules, a resonant capacitor C11, a resonant inductor L11, a dual-output high-frequency isolation transformer TR1, two independent high-frequency rectifier bridges ZD1 and ZD2, and filter capacitors C21 and C22. V11, V12, V13, V14 semiconductor power modules constitute 11, 12, 13, 14 input PWM drive of the H-bridge inverter. Changing the PWM drive can control the output voltage of the DC power supply.

[0097] The dual pulse generating circuit is powered by an adjustable dual isolated output DC power supply. In the specific circuit, the positive polarity end of the filter capacitor C22 of the DC power supply is connected to one end of the semiconductor power module V22, and the other end of the semiconductor power module V22 is connected to the negative polarity end of the filter capacitor C21 of the DC power supply. The positive polarity end of the filter capacitor C21 of the DC power supply is connected to one end of the semiconductor power module V21, and the other end of the semiconductor power module V21 is connected to one end of the primary coil of the pulse boost transformer TR2, and the other end of the primary coil TR2 of the pulse boost transformer is connected to the negative polarity end of the filter capacitor C22 of the DC power supply, forming a DC bus cascade dual pulse generating circuit system. The equivalent circuit is as follows: Figure 3 As shown. The transformer leakage inductance Ls is hidden in the transformer coil. Each loop of the double pulse generating circuit is also connected in parallel with a diode D21, D22, respectively, to provide protection after one of the semiconductor power modules in the double pulse generating circuit fails.

[0098] The semiconductor power modules V21 and V22 of the double pulse generating circuit are driven and controlled by PWM1 and PWM2. PWM1 drives the access control point 21, and PWM2 drives the access control point 22. The width Pw of PWM1 and PWM2 is the same, which is related to the leakage inductance Ls of the pulse boosting transformer TR2, the transformation ratio N of the pulse boosting transformer, and the capacitor C31 of the pulse energy storage circuit. The driving width Pw is greater than or equal to half of the resonant period of the product of the leakage inductance Ls of the pulse boosting transformer TR2, the transformation ratio square and the capacitor C31 of the pulse energy storage circuit, that is, When the semiconductor power module V21 and the semiconductor power module V22 of the double pulse generation circuit work in the bus cascade multiplication mode, the equivalent circuit schematic diagram is as follows: Figure 3 As shown, PWM1 and PWM2 drivers must be completely synchronized. The rising and falling edge change time errors of PWM1 and PWM2 drive waveforms must be controlled within 20ns, forming a bus cascade multiplication, and the pulse power supply output peak voltage is doubled. The output waveform is as follows Figure 5 The semiconductor power module V21 and the semiconductor power module V22 of the double pulse generation circuit can also work in the non-busbar cascade multiplication mode. The equivalent circuit schematic diagram is shown in FIG. Figure 4 As shown, there is only one drive output and the other is completely closed. When PWM1 drive or PWM2 drive output is in non-bus cascade multiplication mode, the pulse power supply output peak voltage is only half of the bus cascade multiplication mode. The output waveform is as follows Figure 6 The non-busbar cascade multiplication mode can be applied to situations where the load needs to run at a lower voltage under certain working conditions, and when one of the semiconductor power modules 1 fails to drive, so that the pulse power supply can retain a certain pulse voltage output capacity before shutting down for maintenance.

[0099] A reverse diode is connected in parallel next to the semiconductor power module V21 and the semiconductor power module V22 of the double pulse generating circuit. After the switch in the semiconductor power module V21 and the semiconductor power module V22 is disconnected, the reverse pulse current of the pulse generator is recharged through the reverse diode and flows back into the filter capacitors C21 and C22 of the pulse power supply.

[0100] The dual pulse generating circuit can only be used for unipolar pulse power supply output, positive or negative output. The change of the positive and negative polarity of the pulse power supply output only requires changing the two connection points of the primary coil of the pulse step-up transformer TR2. Exchanging them will cause the change of the positive and negative polarity of the pulse power supply output.

[0101] The pulse boost transformer TR2 with integrated magnetic core reset, the primary coil of the pulse boost transformer TR2 is connected to the double pulse generating circuit, the secondary coil of the pulse boost transformer TR2 is connected to the pulse energy storage capacitor C31, and the capacitance of the pulse energy storage circuit capacitor C31 is greater than or equal to the capacitance of the load capacitor CZ. The low voltage pulse passes through the primary coil of the pulse boost transformer TR2, is coupled through the magnetic core of the pulse boost transformer TR2, and the secondary coil of the pulse boost transformer TR2 outputs a high voltage pulse. The primary of the pulse boost transformer TR2 is also provided with a reset coil, and the number of turns of the reset coil is 1 turn. The Reset1 reset circuit is connected to the reset coil. Assuming that the pulse power supply outputs positive polarity, after a pulse output ends, the magnetic core of the pulse boost transformer TR2 is in the +Br~+Bm interval of the magnetic core BH curve, and the magnetic core Reset1 reset circuit is reversely reset to reset the magnetic core to the -Br~-Bm interval of the magnetic core BH curve. When the next pulse is output, the available interval of the magnetic core BH curve is from the -Br~-Bm interval to the +Br~+Bm interval, which greatly improves the utilization rate of the magnetic core of the pulse boost transformer. At the same time, the increase of △B can greatly reduce the number of turns of the pulse boost transformer coil, control the leakage inductance of the pulse boost transformer, and improve the performance of the pulse boost transformer.

[0102] The integrated magnetic core reset magnetic switch MZ1 is a pulse rising edge control circuit, and the integrated magnetic core reset magnetic switch MZ2 is a pulse width and falling edge control circuit. Since the dual pulse generation circuit can only be used for unipolar pulse power supply output, the magnetic cores of the pulse rising edge control magnetic switch MZ1 and the pulse falling edge magnetic switch MZ2 also work in the same quadrant of the BH curve, the magnetic core is biased, the working range of the magnetic core BH curve is between -Br~-Bm or the working range is between +Br~+Bm, the working range of the magnetic core is narrow, resulting in a small value of the magnetic core magnetic density △Bm, In the formula, the value of the magnetic core magnetic density △Bm is small, and the number of turns of the magnetic switch coil N needs to be increased. The increase in the number of turns of the magnetic switch coil will increase the inductance after the magnetic switch is saturated, resulting in a sharp drop in the performance of the magnetic switch. The reset coils set for the pulse rising edge control magnetic switch MZ1 and the pulse falling edge magnetic switch MZ2 are respectively set. Since the interval between the pulse rising edge and the pulse falling edge is the pulse width time, which is less than 1us, the reset coil of the pulse rising edge control magnetic switch MZ1 is connected in series with the reset coil of the pulse falling edge magnetic switch MZ2, and share a magnetic core Reset2 reset circuit. Assume that the pulse power supply outputs positive polarity. After a pulse output ends, the magnetic switch core is in the +Br~+Bm interval of the core BH curve. The core reset circuit reversely resets the core to reset the core to the -Br~-Bm interval of the core BH curve. When the next pulse is output, the core BH curve can be used from the -Br~-Bm interval to the +Br~+Bm interval, which greatly increases the value of the magnetic switch △Bm, greatly reduces the number of turns of the magnetic switch coil, reduces the inductance after the magnetic switch is saturated, and improves the performance of the magnetic switch. When the pulse power supply outputs negative polarity, the magnetic switch core interval is opposite, and the principle is the same as the positive polarity output of the pulse power supply. The reset coil of the MZ1 and MZ2 magnetic switches, because the magnetic switches work in a high-voltage pulse state, before the saturation of the MZ1 and MZ2 magnetic switches, the MZ1 and MZ2 reset coils will also generate a pulse voltage through the magnetic core coupling. In order to reduce the pulse induced voltage on the MZ1 and MZ2 reset coils and reduce the winding process of the MZ1 and MZ2 reset coils, the reset coils of the MZ1 and MZ2 magnetic switches are designed to be 1 turn. The insulation withstand voltage of the reset coils of the MZ1 and MZ2 magnetic switches is greater than the highest peak voltage value of the magnetic switch, and at the same time greater than the effective voltage value of the magnetic switch working at the highest peak voltage and maximum operating frequency. The core BH curve is as follows Figure 8 shown.

[0103] The DC bus peak-multiplied adjustable nanosecond pulse power supply solution can not only improve the nanoscale pulse voltage performance, but also has the application of reducing the cost of the reactor.

[0104] An application example of a DC bus multiplication nanosecond pulse power supply and control method: processing the same gas flow, the same reactor height, different discharge distances, 50mm diameter reactor and 100mm diameter reactor, such as Fig. 9As shown. When the flue gas volume and height treated by the reactor remain unchanged, with the same effective flow cross-section, the discharge tube diameter is changed from 50mm to 100mm, the tube thickness remains unchanged at 1mm, and the discharge electrode diameter remains unchanged at 20mm, the 100mm reactor has about 4.6 times fewer discharge electrodes and a 4.6 times fewer weight of discharge tubes than the 50mm reactor, and about 2.3 times fewer weight of discharge tubes. Increasing the discharge distance of the reactor can effectively reduce the weight of the reactor and reduce material costs. At the same time, the reduction in the number of discharge tubes and discharge electrodes can also greatly reduce the processing and manufacturing costs.

[0105] In order to reduce the cost of the reactor, the discharge electrode diameter remains unchanged at 20mm, and the reactor is enlarged from 50mm to 100mm. The discharge distance of the reactor is increased from 15mm to 40mm, which is about 2.67 times. The voltage value output by the nanosecond pulse high-voltage power supply also needs to be increased by at least 2.67 times. The corresponding pulse output peak voltage needs to be increased from 30KV to about 80KV, and the nanosecond pulse high-voltage power supply needs to be redesigned. The typical method is to increase the transformation ratio N of the pulse booster transformer, but the method of increasing the transformation ratio of the pulse booster transformer will cause the equivalent capacitance value of the reactor to change. The converted equivalent capacitance value of the reactor is the square of the transformation ratio. Increasing the transformation ratio of the high pulse booster transformer will cause N 2 The capacitance value of C is very large. As the transformation ratio increases, the leakage inductance of the pulse booster transformer will also increase, affecting the rising edge and pulse width of the pulse, causing changes in the power supply characteristics and worsening the application effect. The DC bus multiplier peak adjustable nanosecond pulse power supply solution is adopted. Through the adjustable dual isolated output DC power supply, the approximately 530V DC voltage obtained by 380V 50HZ industrial frequency three-phase power rectification is increased to 950V DC voltage output, matched with a 1700V IGBT semiconductor module, and the dual pulse generation circuit bus cascade multiplication solution, the operating voltage of the pulse generator is further increased to 1900V, and the operating voltage is increased by 3.58 times. This can be achieved without changing the transformation ratio of the pulse booster, and there is still room for further increasing the reactor discharge distance and reducing costs.

[0106] Special statement: The "embodiment" and the like described in this specification refer to the specific features, elements or characteristics described in conjunction with the embodiment included in the embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not limit the specific reference to the same embodiment. In other words, when describing a specific feature, element or characteristic in conjunction with any embodiment, it is claimed that such feature, element or characteristic is implemented in conjunction with other embodiments and is included in the scope of the claims for protection of the present invention; The embodiment describes the present invention with reference to multiple explanatory embodiments of the logical architecture and ideas of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can design many other modifications and implementation methods within the framework of the technical solution of the present invention, and can make various non-essential modifications and improvements to the key points of the technical solution. For those skilled in the art, other uses will also be obvious, and non-substantial changes or replacements that can be easily thought of for implementation will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A DC bus multiplication nanosecond pulse power supply, comprising a three-phase rectifier filter with integrated buffer circuit, an adjustable dual-isolated output DC power supply, a dual pulse generating circuit, a pulse boosting transformer with integrated magnetic core reset, a pulse energy storage circuit, a pulse rising edge control circuit with integrated magnetic core reset, and a pulse width and falling edge control circuit with integrated magnetic core reset, characterized in that: The adjustable dual-isolated output DC power supply controls and improves the matching of the pulse DC voltage with the voltage level of the semiconductor power module of the dual pulse generating circuit. The DC bus cascade multiplication of the dual pulse generating circuit doubles the pulse DC voltage. The working range of the magnetic core in the BH curve is improved through the pulse boost transformer of the integrated magnetic core reset, the pulse rising edge control circuit of the integrated magnetic core reset, and the pulse width and falling edge control circuit of the integrated magnetic core reset. The operating currents of the two groups of filter capacitors in the double pulse generation circuit and the operating currents of the two semiconductor power modules are controlled so as to simultaneously meet the requirements of the maximum average current value allowed for continuous operation and the maximum pulse current value allowed for continuous operation, and the two control operation formulas are established at the same time: Where: I VA The maximum average current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I VP The maximum pulse current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I CA The maximum average current value allowed for continuous operation of the two groups of filter capacitors; I CP The maximum current value allowed for two groups of filter capacitors to work continuously; U DCa , U DCb The two rated voltage values ​​of the adjustable dual isolated output DC power supply; C P1 is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; N is the transformation ratio of the pulse boost transformer; L S is the leakage inductance of the pulse boost transformer; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

2. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The adjustable dual-isolated output DC power supply improves the DC voltage after rectification of the three-phase industrial frequency power grid. The dual-pulse generating circuit provides two adjustable isolated and independently output DC power supplies. The transformation ratio of the dual-output high-frequency isolation transformer TR1 configured inside the adjustable dual-isolated output DC power supply is matched with the voltage level of the semiconductor power module in the dual-pulse generating circuit. At the same time, it is used for cascading during the operation of the dual-pulse generating circuit to achieve doubling of the DC bus of the pulse power supply.

3. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The adjustable dual-isolated output DC power supply is provided with a DC power supply by a three-phase rectifier filter with an integrated buffer circuit, including an H-bridge inverter composed of V11, V12, V13, and V14 semiconductor power modules, a resonant capacitor C11, a resonant inductor L11, a dual-output high-frequency isolation transformer TR1, two independent high-frequency rectifier bridges ZD1 and ZD2, and filter capacitors C21 and C22; V11, V12, V13, and V14 semiconductor power modules form an input PWM drive of the H-bridge inverter, and changing the PWM drive can control the magnitude of the DC power supply output voltage.

4. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The total output power P of the adjustable dual-isolated output DC power supply DC The regulation control meets the following formula conditions: P DC is the total output power of the adjustable dual isolated output DC power supply; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

5. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The two groups of filter capacitors in the dual pulse generating circuit have the following functions: a. DC filtering for high-frequency rectification; b. voltage balancing for the two loops of the dual pulse generating circuit; c. energy storage capacitors for the pulse generator; d. recovery of residual energy from the resonance of the pulse boosting transformer and the pulse energy storage circuit; two groups of filter capacitors C for the adjustable dual isolated output DC power supply. DCa , C DCb The capacitance value is equal, the capacitance error is less than ±1%, and the capacitance value is Choose between: C P1 is the capacitance of the energy storage capacitor connected to the secondary side of the pulse boost transformer, and N is the transformation ratio of the pulse boost transformer.

6. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: During the operation of the nanosecond pulse power supply, the adjustable dual-isolated output DC power supply adjusts the operating frequency of the H-bridge inverter composed of V11, V12, V13, and V14 semiconductor power modules in real time, changes the voltage of the dual-isolated output DC power supply, and controls the change of the output peak voltage of the nanosecond pulse power supply.

7. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The reset circuit of the pulse boost transformer with integrated magnetic core reset is isolated from the power grid by an isolation transformer, which can improve the anti-interference ability. It adopts DC power supply. The higher the pulse repetition frequency, the higher the reset voltage. The reset voltage U1 of the magnetic core of the pulse boost transformer is adjusted and controlled. reset Satisfies the following formula: U1reset is the reset voltage of the pulse boost transformer core, N1 is the number of turns of the pulse boost transformer reset coil, △B1 is the difference between the magnetic flux density of the pulse boost transformer core -Bm and +Bm, S1 is the cross-section of the pulse boost transformer core, and Ts is the cycle time corresponding to the maximum repetition frequency of the double pulse generating circuit.

8. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The pulse boost transformer for integrated magnetic core reset, the pulse rising edge control circuit for integrated magnetic core reset and the pulse width and falling edge control circuit for integrated magnetic core reset are used to improve the working range of the magnetic core in the BH curve.

9. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The operating currents of the two groups of filter capacitors and the two semiconductor power modules of the control double pulse generating circuit are optimized to the following two formulas for the convenience of automatic control program operation: Where: I VA The maximum average current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I VP The maximum pulse current value allowed for continuous operation of the semiconductor power module in the double pulse generation circuit; I CA The maximum average current value allowed for continuous operation of the two groups of filter capacitors; I CP The maximum current value allowed for two groups of filter capacitors to work continuously; U DCa , U DCb The two rated voltage values ​​of the adjustable dual isolated output DC power supply; C P1 is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; N is the transformation ratio of the pulse boost transformer; L S is the leakage inductance of the pulse boost transformer; C P1 U is the capacitance of the energy storage capacitor connected to the secondary of the pulse boost transformer; P1 The maximum peak voltage on the energy storage capacitor connected to the secondary side of the pulse boost transformer, is the maximum repetition frequency of the double pulse generating circuit.

10. A DC bus multiplication nanosecond pulse power supply according to claim 1, characterized in that: The equivalent series resistance ESR of the filter capacitor in the DC bus multiplier nanosecond pulse power supply circuit is less than 60 μΩ, and the resistance specification of the equivalent series resistance is calculated using the following formula: ESR = tanδ / (2π×f×C) Where: tanδ represents the loss tangent, f is the pulse operating frequency, and C is the capacitor capacitance.

Images