Energy losses in the prebreakdown stage of discharge evolution in high-voltage hydraulic systems

The electro-discharge method of treatment is employed in industry production procedures when effects are exerted by electric discharge in liquid. High voltage (HV) electro-hydraulic systems are used to implement the method. Production procedures usually involve industrial-grade water having high value of the specific conductivity (j /spl ges/ 10/sup -3/ Ohm/sup -1/ cm/sup -1/). Some procedures and techniques involve solutions of higher conductivity, e.g. cement solutions or concrete mixtures. The problem of electro-discharge method implementation with these kinds of medium is high energy losses during prebreakdown stage of discharge evolution. So it requires higher energy values of a single pulse and consequently leads to higher total energy consumption, lower system reliability and so on. The technique of losses determination is necessary to develop measures for their decrease. This report presents the calculation of energy losses during the prebreakdown stage of discharge evolution in HV electro-hydraulic systems. Following parameters were taken for calculations: voltage Uo/spl sim/30-50 kV; working gap length 1 cm to 10 cm; pulse energy W /spl sim/ 0.5-5 kJ. The coax configuration of electrodes with the partially stripped HV electrode was considered. Suggested calculation technique for energy losses for coax electrode design during the prebreakdown stage of discharge will allow to estimate energy losses during the prebreakdown stage for different electrode configurations as well when known equations for the geometrical factor of corresponding electrode designs are used.