Aqueous-solution high-voltage resistors: Development, study, and application (review)

Abstract

Development, studies, and applications of resistors based on aqueous solutions of salts, acids, and their mixtures are reviewed. Aqueous-solution resistors (ASRs) have a number of advantages as compared to resistors of other types: their bulk electric strength reaches 300 kV/cm for pulses of microsecond duration, their energy dissipation in a unit mass of a solution is an order of magnitude higher than that in metals, a liquid recovers rapidly its electric strength after a breakdown, the resistance value can be rapidly adjusted by replacing an electrolyte, resistors can be shaped arbitrarily, their inductance can be as low as a few fractions of 1 nH, they can be used in circuits operating at frequencies of up to ∼1 GHz, they are fire-and explosion-proof, are simple to manufacture, and are inexpensive. The electric characteristics and behavior of solutions in fields of up to 50 kV/cm are refined. A list of combinations of electrode materials and dissolved substances, which operate for a long time, is presented. Criteria are given for considering the permittivity of water in the calculation of the skin-layer depth in a solution. The moisture proofness of ASR cases made of polymer materials is examined. A set of formulas for engineering calculations of several characteristics of ASRs is presented. The procedures of preparing the components, the ASR assembly, and their testing for tightness are described. The electric and service-life characteristics are presented. Along with other ASRs, much attention is being given to the hermetically sealed high-voltage small ASRs developed at the Russian Federal Nuclear Center (VNIIEF). They are serviceable in any positions in volumes with rarefied and compressed gases and oil insulation. Heat-induced changes in the volume of the solution were compensated by the following operations: changes in the geometry of the polymer case of the ASR within the limits of elastic deformations of its walls; profiling of cavities in the electrodes’ walls, so that no gas penetrates from them into the solution at an arbitrary ASR position; and separation of the solution from a hermetically sealed vapor-gaseous cavity in the electrode by an elastic diaphragm. Versions of ASR designs and their characteristics are presented for the following situations: limitation of currents in electric circuits at voltage of up to 100 kV; simulation of high-power loads, including a current of up to 300 kA of a pulsed electron beam; damping of electric oscillations and suppression of reflected pulses; a specified distribution of an electric field along the lengths of insulators for a voltage as high as ∼ 3.5 MV; measurements of parameters of pulse voltage amplitudes of up to ∼2 MV; the application of ASRs as high-voltage dynamic resistive-capacitive elements in circuits of voltage-multiplying generators for reducing the delay time of their operation; etc. This information, systemized for the first time, will be useful for specialists in development, research, and application of ASRs designed for different purposes.