All solid state high voltage nanosecond pulse power supply
Technical field
The invention belongs to power technique fields, be specifically related to a kind of all solid state high voltage nanosecond pulse power supply.
Background technology
Many applications all need to produce the pulse power of high-voltage pulse.High current particle beam accelerator, high power pulsed laser, High-Power Microwave, material surface are handled and ion injects, flash X-ray is taken a picture, pulsed plasma discharges and commercial Application etc. is the application example that needs high-voltage pulse.In legacy system, the pulse power uses capacitor, inductor etc. to carry out energy storage, and the method for use cascade or pulse transformer etc. boost, and use trigger tube and thyratron etc. to carry out switch control.
Usually adopt the principle of Marx generator and form the pulse power of the above-mentioned type.The Marx generator is a kind of through a group capacitor charged in parallel is produced then the circuit of high-voltage pulse to these capacitors in series discharges.Shown in Figure 1 is the instance of typical Marx generator.
After capacitor 104 is fully charged, apply trigger impulse voltage can for usually first order ball crack, make first order ball crack puncture, such two capacitors effectively are together in series and cause next stage ball crack to puncture.Very fast, all ball cracks puncture, so capacitor 104 is connected in series and high-voltage pulse is passed to load 108.Usually adopt transformer to capacitor 104 chargings.In some embodiments, the resistance 102 that has replaced charging current limiter and discharge buffer action with inductance.The ball crack can use other gas switchs to substitute, like rotary switch, and insufflation switch, thyratron or counterfeit spark switch etc.
The common using gases switch of traditional M arx generator though quite high crest voltage and peak current, switching speed faster can be provided, is all having very big limitation aspect repetition rate, stability and life-span, overall system efficiency is also very low.In addition,, make the Marx generator that very large volume and weight arranged when output voltage reaches hundreds of kilovolts, and have bigger ground connection parasitic capacitance owing to adopt power frequency charging device and bigger current-limiting resistance or inductance.Parasitic capacitance can increase the rising/fall time of potential pulse.In order to satisfy the high voltage requirement, adopt transformer oil to insulate usually, this just makes maintenance work become complicated.
Along with the development of power electronics semiconductor solid-state switching device in recent decades and progressively ripe, a lot of researchers both domestic and external begin to develop and adopt the high-voltage pulse generator of semiconductor switch as main switch.Last century, the nineties just had many scholars to propose the potential solution of the direct serial connection technology of various semiconductor switchs latter stage, and had carried out a large amount of experiments.But more than ten years have gone over still not make a breakthrough, the direct serial connection technology of semiconductor also not seen widespread use in commercial power.The difficult point of the direct serial connection technology of semiconductor switch is that each switching tube opening or the transient state of shutdown moment is all pressed problem, because this problem never is well solved, has restricted its practical application.
Also there is the researcher to substitute the gaseous state switch in traditional Marx generator, constructs a kind of novel Marx generator with semiconductor switch.The application of semiconductor switch has overcome traditional Marx circuit in some shortcomings aspect repetition rate, stability and life-span, and the transient state that exists when not existing semiconductor switch directly to connect to use is all pressed problem.Also have big gap but semiconductor switch is compared with the gaseous state switch at aspects such as switching speed, through-current capability and withstand voltage levels, therefore can not replace traditional Marx well in most of Application for Field.
Summary of the invention
The object of the present invention is to provide that a kind of volume is little, the life-span is long, failure rate is low, pulse duration and amplitude are easy to adjust, rising edge is less than all solid state high voltage pulse powers of 100 nanoseconds.
The all solid state high voltage nanosecond pulse power supply that the present invention proposes is divided into following two parts: series connection booster circuit and narrowing circuit.Wherein, the series connection booster circuit is connected in series by a series of voltage cell and forms, and realizes boost function.Each voltage cell comprises the capacitor that is connected with the switch that can turn on and off (such as the classes of semiconductors switch); The capacitor of a series of voltage cell forms a capacitor group; Adopt a part (being called charge switch) in the above-mentioned switch to the capacitor charged in parallel, another part (being called discharge switch) makes the capacitors in series discharge; Narrowing circuit is made up of with the mode that is connected in series intermediate energy storage electric capacity (or sharpening capacitor) and magnetic switch (saturable reactor just); Can further reduce to connect rise time of potential pulse of booster circuit output, play the effect of pulse compression.
In series connection booster circuit when work, if be in charged state, discharge switch all turn-offs, and charge switch is all connected, for the capacitor of each voltage cell provides charging current.If be in discharge condition, discharge switch is all connected, and charge switch all turn-offs, the capacitors in series of each voltage cell that the has been full of electricity output voltage pulse of getting up.Such advantage is, can reduce system bulk, thereby reduce some parasitic capacitance relevant with traditional Marx generator to the capacitor charging under the situation of not using inductor, resistor.
Through the diode that is connected with each voltage cell, can form the path of charging current of condenser, and can be under the situation that some discharge switches lost efficacy bypass correspondent voltage unit, make system still can export the potential pulse that peak value reduces.When capacitor was charging or be charged, the discharge switch between the continuous electric container was in off state to prevent discharge.When discharge switch was connected, capacitors in series connected and discharge.At interdischarge interval, charge switch turn-offs.For capacitor is charged once more, discharge switch breaks off and charge switch recloses.
The potential pulse of series connection booster circuit output is delivered to above the intermediate energy storage electric capacity (or sharpening capacitor) of narrowing circuit, just middle storage capacitor (or sharpening capacitor) is charged.The capacity of intermediate energy storage electric capacity equals the equivalent capacity after each the cell capacitance series connection of Marx generator, the whole energy in its store M arx generator; The capacity of sharpening capacitor is much smaller than the equivalent capacity of Marx generator, so a storage area energy.When charging proceeds to a certain moment, the saturable reactor that is connected with intermediate energy storage electric capacity (or sharpening capacitor) by the insatiable hunger state with become saturation condition, thereby accomplished magnetic switch from being disconnected to the transformation of connection.Then intermediate energy storage electric capacity (or sharpening capacitor) through the magnetic switch connected to load discharge.Intermediate energy storage electric capacity discharges whole energy of storage, sharpening capacitor then with the Marx generator together to load discharge.Under preceding a kind of situation, the width of system's output voltage pulse is determined by narrowing circuit and load characteristic jointly; Under latter event, the rising edge of narrowing circuit decision potential pulse, the duration of Marx circuit decision potential pulse.Under the situation of appropriate design; The speed of opening of magnetic switch is compared fast a lot with the semiconductor switch that identical electric pressure series connection is used; Therefore can shorten the rise time of the potential pulse of aforementioned series connection booster circuit output, from dropping in 100 nanoseconds hundreds of nanosecond even number microsecond.In addition, higher through-current capability of magnetic switch and the withstand voltage level deficiency that also remedied the pulse of simple dependence semiconductor switch output voltage.
Can adjust the amplitude of output voltage pulse through the operating state of certain or certain several voltage cell in the control series connection booster circuit, and the passages through which vital energy circulates punching press is contracted, and can not be a greater impact after the circuit compression rise time of potential pulse.That is to say, one or more voltage cell is not worked, thereby do not influencing the amplitude that changes potential pulse under the situation that produces the potential pulse ability.Simultaneously, the inefficacy of certain or certain several unit can not stop pulse generator to produce pulse.
When the electric capacity of narrowing circuit was sharpening capacitor, the ON time that changes semiconductor switch in the Marx generator can be adjusted the width of output voltage pulse.
Because the employing of technique scheme, the present invention compared with prior art has following advantage:
Save reactor, resistor general in traditional Marx pulse generator, replaced semiconductor switch device.This method has reduced system bulk, has reduced the influence of parasitic capacitance.
Reducing of system bulk, the feasible more voltage cell of can connecting, thus therefore can the lower dc charging power supply paired pulses generator charging of working voltage produce potential pulse greatly.
With respect to traditional Marx generator, the generator life-span of employing semiconductor switch device is longer, operating frequency is higher.
The inefficacy of certain or certain several voltage cell can not stop pulse generator to produce pulse in the system.
There is narrowing circuit in system in output stage, with the output pulse of magnetic switch compression semiconductor Marx generator.The speed of opening of magnetic switch is compared fast a lot with the semiconductor switch that identical electric pressure series connection is used, therefore can shorten the rise time of the potential pulse of semiconductor Marx circuit output, from dropping in 100 nanoseconds hundreds of nanosecond even number microsecond.
Magnetic switch has stronger through-current capability and higher withstand voltage grade, has remedied the deficiency of simple dependence semiconductor switch output voltage pulse.In addition, magnetic switch is non-maintaining basically, and failure rate is extremely low.
Through the conducting and the shutoff of semiconductor switch in the control system, can change the amplitude and the pulsewidth of output voltage pulse easily.
Description of drawings
Fig. 1 is the circuit structure of typical Marx generator;
Wherein: the 100-Marx generator; The 102-charging resistor; The 104-capacitor; 106-ball crack; The 108-load; The 110-charging voltage.
Fig. 2 is the general structure block diagram of all solid state high voltage nanosecond pulse power supply;
Wherein: 200-pulse power system; The 202-switched capacitor bank; The 204-narrowing circuit; The 206-load; The 208-switch driver; The 210-control signal; The 212-voltage cell; The 214-semiconductor switch; 216-intermediate energy storage electric capacity; The 218-magnetic switch.
Fig. 3 is the execution mode block diagram of all solid state high voltage nanosecond pulse power supply;
Wherein: 300-pulse power system; The 302-DC power supply; 304,306 and the 308-switch drive; 310,312 and the 314-charge switch; 316,318 and the 320-switch drive; 322,324 and the 326-discharge switch; 328 with 330-charging current loop; 332,334 and the 336-capacitor; 338,340 and the 342-diode; 344-intermediate energy storage electric capacity (or sharpening capacitor); The 346-magnetic switch; The 348-load.
Fig. 4 is the execution mode block diagram of all solid state high voltage nanosecond pulse power supply of generation negative voltage pulse;
Wherein: 400-pulse power system; The 402-DC power supply; 404,406 and the 408-switch drive; 410,412 and the 414-charge switch; 416,418 and the 420-switch drive; 422,424 and the 426-discharge switch; 428,430 and the 432-capacitor; 434,436 and the 438-diode; 440-intermediate energy storage electric capacity (or sharpening capacitor); The 442-magnetic switch; The 444-load; 446,448 and the 450-voltage cell.
Fig. 5 is the execution mode block diagram of all solid state high voltage nanosecond pulse power supply of generation positive voltage pulse;
Wherein: 500-pulse power system; The 502-DC power supply; 504,506 and the 508-switch drive; 510,512 and the 514-charge switch; 516,518 and the 520-switch drive; 522,524 and the 526-discharge switch; 528,530 and the 532-capacitor; 534,536 and the 538-diode; 540-intermediate energy storage electric capacity (or sharpening capacitor); The 542-magnetic switch; The 544-load.
Embodiment
The present invention relates to be used to produce the system and method for potential pulse.The present invention can control the amplitude of potential pulse, the duration of potential pulse, and make the rise of output voltage edge less than 100 nanoseconds.
Comprise a series of voltage cell in the execution mode of the present invention, and be used for the intermediate energy storage capacitor (or sharpening capacitor device) and the magnetic switch of compression pulse with series capacitors and switch.Charge switch in each voltage cell provides path for the charging current that applies through diode.The advantage of sort circuit structure is to adopt reactor general in traditional pulse generator, resistor and power frequency charge power supply, can export the potential pulse with fast rise edge simultaneously.In addition, system bulk reduce to have reduced the ground connection parasitic capacitance relevant with system and method described here, this makes the more voltage cell of can connecting.
Fig. 2 illustrates and is used to produce and to the pulse generator of load transferring high voltage pulse or the general structure block diagram of system.
Particularly, pulse current 200 produces and to load 206 transferring high voltage pulses.In system 200, switched capacitor bank 202 is connected through the mode of semiconductor switch 214 with parallel connection (during charging) or series connection (during discharge) by a plurality of voltage cell 212.Voltage cell 212 is used to store the potential pulse that passes to narrowing circuit 204.218 series connection constitute narrowing circuit 204 with magnetic switch by intermediate energy storage electric capacity (or sharpening capacitor) 216.
Voltage cell 212 is connected with the semiconductor switch of controlling through switch driver 208 214 usually.Through the control signal of by-pass cock driver 208, switch driver 208 opening/closing semiconductor switchs 214.State decision voltage cell 212 chargings of semiconductor switch 214 are still to narrowing circuit 204 discharges.In practical implementation, thus such structure decrease the influence of the parasitic capacitance more voltage cell of can connecting.The more voltage cell owing to can connect, 212 chargings produce big potential pulse to voltage cell thereby therefore can use lower direct voltage.The all or part of energy that intermediate energy storage electric capacity (or sharpening capacitor) 216 transmitted during with voltage cell 212 discharged in series temporarily stores, and the compression through magnetic switch 218 is delivered to load 206.In practical implementation, this method has remedied slow, the electric current smaller defect of the high-voltage pulse rising edge of exporting when using semiconductor switch to make discharge switch.
In the execution mode of system 200, the state through control switch 214 carries out charged in parallel and makes the voltage cell discharged in series voltage cell.An advantage of system 200 is can not stop this system to load 206 transferring high voltage pulses under the situation of the discharge switch inefficacy in one or more voltage cell 212 and the semiconductor switch 214.Owing to the characteristic of magnetic switch, can make system under the situation that output voltage reduces, the rising edge of a pulse that is similar to when still keeping with rated voltage output.System's 200 transmission positive voltage pulses perhaps transmit negative voltage pulse.
Fig. 3 illustrates the execution mode of high-voltage pulse generator.Comprise three voltage cell in this execution mode, but as stated, those of ordinary skill in the art should be realized that, can comprise more or less level.
To capacitor 332,334 and 336 chargings the time, through the control signal of switch drive 308,306 and 304, charge switch 310,312 and 314 is in on-state; Through the control signal of switch drive 320,318 and 316, discharge switch 322,324 and 326 is in off state.Path 328 expression is from the current path that capacitor 336 is charged of DC power supply 302.Simultaneously, DC power supply 302 through path 330 transmission currents so that capacitor 334 is charged.To the electric current of capacitor 332 charging flow through charge switch 314,312 and 310 and diode 342,340 and 338.Diode 342,340 and 338 is opened the high-voltage pulse and the isolated from power of interdischarge interval generation.Simultaneously, said diode allows pulse to walk around the voltage cell of any inefficacy.
At the capacitor interdischarge interval,, make charge switch 310,312 and 314 be in off state and discharge switch 322,324 and 326 is in on-state through applying corresponding switch drive.Like this, each voltage cell intermediate energy storage electric capacity (or sharpening capacitor) 344 chargings in the paired pulses compressor circuit that are connected in series.After capacitor 344 chargings are accomplished, magnetic switch 346 saturation conductions, 344 pairs of loads of capacitor, 348 discharges form high-voltage pulse.
Magnetic switch 346 is applied in here, has not only that switching speed is fast, through-current capability is strong and the withstand voltage advantages of higher, can also realize high repetition frequency (greater than 1000Hz) and long-life operation (stable 10 a powers pulse that produces above 10).
Fig. 4 expresses the block diagram of the pulse generator that comprises a plurality of voltage cell (also being referred to as level or part).The execution mode of pulse generator shown in Figure 4 is used for producing negative voltage pulse.Comprise three voltage cell in this execution mode, but as stated, those of ordinary skill in the art should be realized that, can comprise more or level still less.Fig. 4 illustrates the charge switch 414,412 of employing through switch drive 404,406 and 408 controls and 410 and the voltage cell 450,448 and 446 that is connected with mode as stated of discharge switch 426,424 through control switch 416,418 and 420 controls and 422, and Fig. 4 also shows intermediate energy storage electric capacity (or sharpening capacitor) 440 and magnetic switch 442.
In this embodiment, switch 410,412 and 414 and switch 422,424 and 426 can be the semiconductor switch of any type as known in the art.Triode thyristor (SCR), dipole electric power triode (BJT), power field effect pipe (Power MOSFET), insulated gate bipolar transistor npn npn (IGBT), static induction transistor (SIT), static induction thyristor (SITH), gate turn off thyristor (GTO) etc. are the embodiment of available switch here.Each voltage cell comprises the switch drive and the switch drive of controlling discharge switch that is used to control charge switch.For example, voltage cell 446 comprises the switch drive 416 that is used to control discharge switch 426.In this embodiment, control the grid of discharge switches 426 through switch drive 416.The grid of switch drive 404 control charge switchs 414.
DC power supply 402 through charge switch 410,412 and 414 and 434,436 and 438 pairs of capacitors 432,430 and 428 of diode charge.Charge with this mode and can use inductor, resistor or isolated supplies general in traditional Marx generator.Switch can be through such as optical fiber coupling, the transformer coupled triggering.
Can under the situation of delay can't connected or exist to the switch of specific voltage unit, the current path of walking around this specific voltage unit be provided by diode 434,436 and 438 diode chain that constitute of series connection, guarantee to still have potential pulse output.
When making magnetic switch, should select the core material that magnetic hysteresis loop rectangle characteristic is good, saturation flux is big, soft magnetic characteristic is good and high-frequency loss is little.Usually there is this different materials of ferrite, amorphous alloy and nanometer crystal alloy available
Fig. 5 illustrates the another kind of execution mode of pulse generator.Fig. 5 is similar to pulse generator shown in Figure 4, and the difference of the two existence is that the pulse generator of Fig. 5 produces positive pulse and the pulse generator generation negative pulse of Fig. 4.Fig. 5 compares with Fig. 4 on circuit structure, has changed the polarity of charge power supply, has changed the direction of charge switch, discharge switch and diode chain.