B.E. Fridman

A Switching System for Capacitive Energy Storage

The system is intended both for synchronous and programmed discharging of large capacitive energy storage systems. As circuit closers, triggered vacuum switches (TVSs) РВУ-43 are used. The TVSs can handle a current of up to 200 kA at a voltage of up to 30 kV and charge of up to 120 C. Each TVS is enclosed in a shielding case with sockets for coaxial cables that connect the switch with the capacitors and the load. Switch-triggering pulses are generated by multichannel high-voltage pulse generators (triggering generators). Each channel is controlled by a programmer via a fiber-optic cable. The programmer operates in conjunction with a computer and provides, in each channel, a prescribed delay of the pulses generated relative to the synchronizing pulse common to the entire system.

Conductors and Contact Connections in Megaampere-Current Electric Circuits

The operation of conductors and contact connections in electric circuits transmitting megaampere-current pulses with durations of tens of microseconds is considered. The permissible conductor-current density is determined from the condition of thermal stability of the high-voltage polymeric insulation. Operating conditions of demountable contact connections for megaampere pulse currents are described, and design examples of such connections operating at a linear current density as high as 80 kA/cm are given. Methods for providing mechanical stability against the action of electrodynamic forces that occur during the passage of megaampere-current pulses are considered.

About the possibility of high pulse currents application in the experiments on dynamic compression of solid bodies

A pulsed power-based compression method of a steel cylindrical ampoule, installed inside a cylindrical liner constructed from metal with high electric conductivity (copper, aluminum) is analyzed. Compression efforts are created due to the pinch-effect in the process of high pulse current flow along the liner. Parameters of the investigated samples and the pulse current, required to obtain high pulse pressure, are determined.

The multimegajoule capacitive energy stores for generating pulses with large current integral

The problems of the design multimegajoule and multimegaampere capacitive energy stores for generating pulses with large current integral are considered. The essence of these problems is described on an example of E7-25 type capacitive energy store of Institute of Problems of Electrophysics of RAS. The E7-25 energy store was tested and it generated the 10 MA current pulse with current integral up to 5.10/sup 9/ A/sup 2/s.

The installation for pulse compression with use of the heavy current pulse discharge

The pressure, arising at passage of the large pulse current through the cylindrical liner, can be used for creation of super-high pressure and pulse compression of specimens. Such pressure is necessary for various physical research, for study of phase conversions of substances. The installation for creation of the pulse pressure in the z-pinch scheme is described in the paper. The installation is connected to the terminal of the E7-25 Capacitive Energy Store and it is designed for 10 MA current pulse with 20 kV voltage. The first test results of the installation are submitted.

E7-25 capacitive energy store for power supplying loads of electro-discharge loads

Summary form only given. A capacitive energy store is described for supplying experiments with electro-discharge launchers and other loads. The designed stored energy is 17.2 MJ, maximum voltage is 25 kV, discharge current range is 10 MA and the frequency of the discharge current oscillations in short circuit is 8 kHz. The store was built on a modular principle. It contains 23 modules, all of which consist of 8 cells. Every cell has capacitors of 94 kJ stored energy and vacuum triggered vacuum switches. Control and synchronization systems of the storage provide remote operation by every module and nonsimultaneous programmed discharge, where triggered switches in cells are switched-on in definite time. The first phase of the store was put in operation with 9 MJ of stored energy (12 modules) and was tested with a 10 MA discharge current.

The experimental installation for z-pinch pulse compression

Summary form only given, as follows. The installation is intended for experimental study of substances phase conversions with super-high pulse pressure. The pressure is created at passage of the large pulse current through the cylindrical heavy liner (z-pinch scheme). The installation is connected to the terminal of the E7-25 type capacitive energy store and its designs on 10 MA current pulse with 20 kV voltage, 100 /spl mu/s. The regimes of dynamic compression are presented, in which there is not over-heating of studying substances. Estimations of the electrodynamical forces, acting on the installations elements, are made.

Arc channel impedance estimation according to voltage and current oscillograms with programmable discharge of capacitive energy store

Summary form only given, as follows. A programmable discharge of capacitive energy stores allows to obtain optimum regimes of energy emission in the load. Characteristic peculiarities of programmable discharge regime are the voltage step change on the load at the moment of regular capacitance module switching on and the existence of several maximums on the current curve in the load in the time gap between modules switching on. Magnitude of the step on the voltage curve gives the possibility of defining existing inductance of the load. Voltage at the moment of current peak allows estimation of ohmic resistance of the load. Working out results of oscillogram records of the E7-25 capacitive store programmable discharge on electric arc in air at atmospheric pressure are presented. High-speed photography of an electric arc in air has demonstrated correlation between measured arc inductance and its form evolution.