The semiconductor based resonant series counterpulse technique for high current opening switches
conference paper
At the Pulse Physics Laboratory, research is being performed to develop an all-semiconductor based counterpulse technique for the controlled interruption of very high currents in inductive storage pulsed power systems. Presently, a repetitive mechanical high current opening/closing switch is applied to commutate current from a storage inductor, charged by a homopolar generator, into an inductive load (e.g. a rail accelerator). At high currents arcs occur between the contacts of the switch during the opening and closing process, which severely damage the contacts. To increase the current level the mechanical switch is able to interrupt (to mega-ampere level), the application of a semiconductor based counterpulse technique looks promising.
To prevent or limit arcing and its inherent damage, the current must be reduced to zero or a low level before opening the mechanical switch. A resonant series counterpulse circuit that will create a counterpulse current through the opening switch is proposed. Then, the net current through the switch reduces to zero and the switch can be opened without damaging the contacts. The series connected counterpulse circuit incorporates units consisting of a capacitor bank of electrolytic capacitors with parallel connected diodes and a thyristor connected in series. Each unit has been designed to generate a current pulse of up to 50 kA. By placing several units in parallel, higher counterpulse currents can be generated.
The paper will shortly discuss the circuit, the construction of a unit and demonstrate the operation of one unit and the parallel operation of two units.
To prevent or limit arcing and its inherent damage, the current must be reduced to zero or a low level before opening the mechanical switch. A resonant series counterpulse circuit that will create a counterpulse current through the opening switch is proposed. Then, the net current through the switch reduces to zero and the switch can be opened without damaging the contacts. The series connected counterpulse circuit incorporates units consisting of a capacitor bank of electrolytic capacitors with parallel connected diodes and a thyristor connected in series. Each unit has been designed to generate a current pulse of up to 50 kA. By placing several units in parallel, higher counterpulse currents can be generated.
The paper will shortly discuss the circuit, the construction of a unit and demonstrate the operation of one unit and the parallel operation of two units.
TNO Identifier
128159
Publisher
TNO
Source title
7th Topical Meeting European Electromagnetic Launch Society, Nottingham, UK, 23-26 September 1996
Collation
13 p.
Place of publication
Rijswijk
Files
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