Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
  • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
  • H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
  • H02M3/07—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
  • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
  • H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
  • H03K17/689—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors with galvanic isolation between the control circuit and the output circuit
  • H03K17/691—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors with galvanic isolation between the control circuit and the output circuit using transformer coupling
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
  • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
  • H03K3/53—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
  • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
  • H03K3/53—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback
  • H03K3/57—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback the switching device being a semiconductor device

Definitions

• the field of the invention is that of the generation of high power pulsed according to the principle of slow storage of a certain amount of energy and its rapid return.
• the pulsed high powers find application in different fields.
• a first field of application is that of pulsed power supplies for lasers, X diodes, magnetrons, electron beams or UV flashes.
• a second area of application is the generation of electromagnetic waves that are useful in radar or electronic jammers.
• simulators such as lightning wave simulators, electromagnetic compatibility or electromagnetic launchers.
• a fourth area concerns the clearance of gases, solids or liquids by pulsed electric field methods, by crown effects or by shock waves, as well as surface treatments.
• a high voltage pulse generator includes a storage capacitor charged through a resistor by a power source. Once the energy is stored, it is quickly returned to the use via a switch triggered for this purpose.
• voltage amplifying devices such as for example a Marx generator
• the principle of a Marx generator consists in charging at an initial voltage V0 n associated capacitors in parallel, and then discharge them after associating them in series by means of switches, so as to apply the voltage n * V0 on the use.
• Two voltage signals are required for the operation of such a high-voltage pulse generator: one relating to the power supply of the generator for charging the capacitor or capacitors, the other corresponding to a signal of control for triggering the one or more switches for discharging and generating the pulse.
• PT-55 generator As an example of a commercial generator, mention may be made of the PT-55 generator from Pacific Atlantic Electronics. This generator is associated with an auxiliary module PT-70 which provides a continuous high voltage signal (7kV) via an HV cable and a control signal (250V) through a coaxial cable. It also includes a Nickel 63 radioactive source (encapsulated in a vacuum bulb) for switching electrical energy.
• auxiliary module PT-70 which provides a continuous high voltage signal (7kV) via an HV cable and a control signal (250V) through a coaxial cable. It also includes a Nickel 63 radioactive source (encapsulated in a vacuum bulb) for switching electrical energy.
• L3 Communications which uses a thyratron (mercury vapor tube) to produce a high voltage pulse of 50kV.
• This generator requires a supply of pressurized air to ensure its stability of operation, a mains power cable and a coaxial cable for the control of thyratron triggering.
• This generator has the disadvantage of a high sensitivity EMC which greatly alters its operation in a disturbed environment.
• L3 Communications also offers the TG-75 generator that operates at 50kV from the 220V / 50Hz network for its power supply and a control signal provided by an optical fiber.
• the object of the invention is a high voltage pulse generator which does not have the drawbacks raised, in particular a generator which is simpler to implement in that it can be controlled by a single one. cable. It proposes for this purpose a pulsed power generation system comprising an input for receiving an input pulse and a high pulse generator.
• a voltage comprising a first input for receiving a signal from the input pulse in a generator charging phase and a second input for receiving a trigger signal of a generator discharge phase, characterized in that it comprises a control circuit connected, on the one hand, to the reception input of the input pulse and, on the other hand, to the second input of the generator, the control circuit being configured to detect the end of the input pulse and to generate a trigger signal upon detection of the end of the input pulse.
• control circuit comprises a shunt circuit configured to detect a positive or negative portion of the derivative of the input pulse, and a trigger circuit configured to provide said trigger signal upon detection, by the shunt circuit, of a positive or negative part of the derivative of the input pulse;
• the trigger circuit comprises a capacitor connected on the one hand to the first input of the generator and on the other hand to the second input of the generator via an open switch in the generator charging phase, the closing said switch being controlled following the detection, by the differentiator circuit, of a positive or negative portion of the derivative of the input pulse;
• said switch is performed through a ferrite pulse transformer arranged between the differentiator circuit and the trigger circuit; it further comprises a voltage booster circuit arranged between the input pulse receiving input and the first input of the generator and configured to provide a continuous high voltage signal at the first input of the generator;
• the generator comprises at least one switch capable of being triggered upon reception, by the second input of the generator, of the trigger signal of a discharge phase of the generator;
• the generator comprises a plurality of synchronously triggered switches on receiving, by the second input of the generator, the trigger signal of a discharge phase of the generator;
• the generator comprises a ferrite pulse transformer comprising a ferrite core traversed by a wire into which the triggering signal of a discharge phase of the generator passes, a plurality of windings being positioned on the toroid, each of the windings being connected to one of the switches;
• the generator is a Marx generator comprising a plurality of capacitors connected to each other so as to be able to be charged in parallel, and to be discharged in series via switches, it further comprises a low voltage signal source connected to the receiving input of the input signal via a coaxial cable.
• the invention also relates to a method for generating high power pulsed by means of a high voltage pulse generator comprising a first input for receiving a signal from an input pulse in a charging phase. of the generator and a second input for receiving a trigger signal of a discharge phase of the generator, characterized in that it comprises the steps of detecting the end of the input pulse, and, following detecting the end of the input pulse, generating and supplying to the second input of the generator a trigger signal of the discharge phase.
• FIG. 1 represents a system for generating pulsed powers according to a possible embodiment of the invention
• FIG. 2 illustrates a possible embodiment of synchronized triggering of switches that can be implemented in the invention
• FIGS. 3a and 3b illustrate the dual polarity operation of a Marx generator that can be used in the invention
• FIGS. 4a and 4b illustrate a high voltage pulse obtained by a generation system according to the invention, according to two different time scales.
• the invention relates to a system for generating pulsed powers 1, comprising an input E1 for receiving an input pulse Ve and a pulse generator 2.
• high-voltage signal Vs comprising a first input EA for receiving a signal Vch directly or not from the input pulse Ve in a generator charging phase and a second input ED for receiving a trigger signal Id of a discharge phase of the generator.
• the input pulse Ve is a low voltage signal typically taking the form of a rectangular pulse.
• a high voltage pulse Vs at the output of the generator 2 has a voltage of amplitude greater than 1 kV, typically an amplitude of the order of a few tens of kilovolt. This amplitude is adjustable: it depends on the duration and / or the amplitude of the input low voltage pulse, the number of stages that can compose the generator 2 and the charge voltage of each stage.
• the system 1 can comprise a voltage booster circuit 6 arranged between the reception input E1 of the input pulse, for example in series with an inductance Ls present at the reception input El , and the first input EA of the generator 2.
• the voltage booster circuit 6 can be configured to supply a high-voltage DC signal to the first input EA of the generator 2. It is for example a DC / DC converter 12V to 1500V.
• the pulsed power generation system 1 according to the invention furthermore comprises a control circuit 3, 4, 5 connected, on the one hand, to the input input reception input E1, and on the other hand on the second input ED of the generator, the control circuit being configured to detect the end of the input pulse Ve and to generate a trigger signal Id on detection of the end of the input pulse Ve.
• the control circuit may in particular comprise a differentiator circuit 3 configured to detect a positive or negative part of the derivative of the input pulse, and a trigger circuit 4 configured to provide said trigger signal Id following the detection, by the differentiator circuit 3, a positive or negative part of the derivative of the input pulse.
• a differentiator circuit 3 configured to detect a positive or negative part of the derivative of the input pulse, and a trigger circuit 4 configured to provide said trigger signal Id following the detection, by the differentiator circuit 3, a positive or negative part of the derivative of the input pulse.
• the differentiator circuit 3 makes it possible to detect a negative or positive part, respectively, of the derivative of the pulse synonymous with the end of the pulse, that is to say the falling edge, respectively the rising edge, of the rectangular pulse.
• the triggering circuit 4 may comprise a capacitor C1 connected to the first input EA of the generator, for example via a first resistor RI, and secondly at the second input of the generator ED via a switch Q1 and a second resistor R2.
• the switch Q.1 is controlled in such a manner as to be open during the charging phase of the generator 2, thus enabling charging of the capacitor C1 via the first resistor R1.
• the switch Q.1 is moreover controlled to close following the detection, by the differentiator circuit 3, of the end of the input pulse, thus allowing the discharge of the capacitor C1 and the generation a current pulse Id serving as a trigger signal for a discharge phase of the generator 2 delivered to the second input ED of the generator 2.
• the differentiator circuit 3 may comprise a first generation branch of a control signal of the triggering circuit 3 and a second branch of processing of the input pulse.
• the second branch derives the input pulse and provides a control signal to the first branch when the derivative is negative.
• the first branch comprises a series RC circuit consisting of a third resistor R3 and a second capacitor C2, the input of which is connected to the input El of the system 1 to allow the storage of energy in the second capacitor in the presence of a pulse Ve on the input El.
• the output of the series RC circuit is connected to the ground by means of two MOSFET transistors (second transistor Q.2 and third transistor Q3) connected in series and with polarities opposite, the second transistor Q2 being of type P and the third transistor Q3 being of type N (mounting type push-pull).
• the midpoint between the transistors Q2, Q3 constitutes the output of the differentiator circuit 3, on which is found, on detection of the end of the input pulse Ve, a signal controlling the closing of the switch Ql of the triggering circuit 4.
• the gates of the transistors Q2, Q3 are moreover interconnected and at a mid-point between a fourth resistor R4 connected to the output of the circuit RC and a fourth transistor Q4 of type N connected to ground and whose gate is connected to the output of the second branch of the differentiator circuit.
• the second branch detects that the derivative of the input pulse is positive or zero, no signal is applied to the gate of the fourth transistor Q4 which is therefore blocked.
• the gates of the second and third transistors Q2, Q3 are then connected to the input E1 via the RC circuit, so that the second transistor Q2 is off while the third transistor Q3 is on.
• the midpoint between the second transistor Q2 and the third transistor Q3 is then connected to ground.
• the second branch detects that the derivative of the input pulse is negative, a signal is applied to the gate of the fourth transistor Q4 which is passing.
• the gates of the second and third transistors Q2, Q3 are connected to ground, with isolation provided by the fourth resistor R4, so that the second transistor Q.2 is on while the third transistor Q.3 is off.
• the midpoint between the second transistor Q2 and the third transistor Q3 is then connected to the output of the circuit RC and then delivers a pulse corresponding to the discharge of the second capacitor C2.
• the second processing branch of the input pulse comprises in series between the ground and the input El of the system 1, a capacitor C3 and a parallel connection of a sixth resistor R6 with a fifth resistor R5 in series with a diode D2 whose cathode is directed towards the mass.
• the signal derived from the signal at the input E1 of the system is found.
• the cathode of a diode D1 is connected to the midpoint between the diode D2 and the fifth resistor R5.
• the primary winding L3 of a transformer is connected, on the one hand, to the anode of the diode D1 and, on the other hand, to the ground by means of a seventh resistor.
• the secondary winding L4 of the transformer is connected, on the one hand, to ground via an eighth resistor R8 and, on the other hand, to the gate of the fourth transistor Q4.
• This arrangement ensures that the gate of the fourth transistor Q4 is powered only on detecting a negative part of the derivative of the signal at the input El of the system, that is to say during a falling edge of a pulse of entry Ve.
• the control circuit also comprises a ferrite pulse transformer 5 arranged between the differentiator circuit 3 and the trigger circuit 4.
• the primary winding L2 of the transformer 5 is connected to the output of the differentiator circuit 3 (midpoint between the second transistor Q2 and the third transistor Q3) and the secondary winding L1 is connected to the first transistor Q1, for example its trigger and its cathode when it takes the form of a thyristor.
• This solution of using a ferrite core as a pulse transformer to trigger a semiconductor switch can also be used to trigger the switch or switches of the generator 2, in particular, when the generator comprises several switches, to achieve a synchronized triggering of the switches on reception, by the second ED input of the generator 2, of the trigger signal Id of a discharge phase of the generator.
• a ferrite core 6 is used as a pulse transformer.
• the primary winding is summed up by a single wire 7 on which passes the current pulse Id serving for the synchronous triggering of the thyristors.
• Two secondary windings 8, 9 are positioned on the torus, each connected to the gate and to the cathode of one of the thyristors T1, T2.
• the trigger currents all have the same shape and their amplitude is directly proportional to that of the trigger current pulse Id.
• the high voltage pulse generator is a Marx generator comprising a plurality of capacitors Ce connected to each other so as to be able to be loaded in parallel, and be discharged in series via switches S1-S4.
• Such a generator has the advantage that a simple inversion thereof makes it possible to change the polarity of the high output voltage pulse without having to modify that of the input pulse.
• FIG. 4a and 4b illustrate a high voltage pulse obtained by a system according to the invention, according to two different time scales.
• FIG. 4a thus illustrates an output pulse Vs of amplitude 30 kV on a resistive load of 2 k ⁇ .
• FIG. 4b illustrates the rising edge of the pulse of FIG. 4a: it is here 35 ns, with a tripping delay (also designated by the term "jitter”) of the generator 1 less than 5 ns.
• jitter also designated by the term "jitter”
• the invention is not limited to the system as previously described but also extends to a method of generating high power pulsed by means of such a system, and in particular to a high power generation method pulsed by means of a high voltage pulse generator comprising a first input for receiving a signal from an input pulse in a generator charging phase and a second input for receiving a signal triggering a discharge phase of the generator, characterized in that it comprises the steps of detecting the end of the input pulse, and, following the detection of the end of the input pulse, generating and supplying to the second input of the generator a trip signal of the discharge phase.
• the invention offers the following advantages.
• the pulsed power generation system can be driven by a single 50 ⁇ coaxial cable. This results in a simplicity of implementation, not requiring to bring high voltage on the control-command frame, or to use an auxiliary power supply or connection to the 220V / 50Hz network.
• stage generator such as a Marx generator
• the use of a stage generator, such as a Marx generator limits the operating voltage of each stage to a level compatible with the use of low power components at low costs.
• the output voltage depends on the number of stages, it is theoretically infinite.
• the triggering of semiconductor switches by ferrite transformers provides both a galvanic isolation of the control circuit and the power circuit (which results in robustness and simplicity of implementation at low cost) and the synchronized triggering of all generator switches.
• the output voltage is adjustable, for example from 20% to 100%.
• the system does not use any radioactive source, pressurized gas, or cooling system. It presents no constraints in terms of EMC.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Generation Of Surge Voltage And Current (AREA)

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• 2014
  • 2014-04-08 FR FR1453100A patent/FR3019700B1/fr not_active Expired - Fee Related
• 2015
  • 2015-04-07 WO PCT/EP2015/057439 patent/WO2015155148A1/fr active Application Filing
  • 2015-04-07 US US15/302,710 patent/US10097085B2/en not_active Expired - Fee Related
  • 2015-04-07 EP EP15741924.3A patent/EP3130077A1/de not_active Withdrawn

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