Design And Experimental Study Of High Voltage Power Supply And Control Device For Wire Electrical Explosion

Nanotechnology rose since the end of the20th century and will lead the new technology revolution in the21th century. Nanometer metal powder possesses many excellent performances, including physical and chemical performances that traditional materials don’t have and unique light, electric, magnetic performances, thus having vast potential for future applications in fields of national economy and national defense. However, due to lack of industrial machinery in preparation, nanometer powder usually has low yield and high price.Based on the method of wire electrical explosion by gas discharge, a set of continuous wire electrical explosion devices was designed in this thesis, to realize continuous, efficient, stable and controllable power preparation. The devices included high-voltage charging system, auto wire feeder, nano-powder collection device and peripheral circuit. The high-voltage charging system integrated voltage doubling rectifying circuit with traditional transformer, which can effectively reduce the volume of traditional transformer and the cost, and suitable voltage doubling rectifying circuit can realize quick charging; wire feed rate was controlled by adjusting input voltage of DC motor; single phase AC converter was adopted to control rotate speed of the powder collection motor, study the relationship between motor rotate rate and powder collection efficiency and determine optimal rotate rate; control circuit and low-voltage protection circuit were included in peripheral circuit for charging voltage, wire feed rate, vacuum supply in explosion chamber and collection, as well as the safety of operating personnel.In the preparation of nano powder with wire electrical explosion, P5100high-voltage probe with attenuation ratio of100and Rogowski Coil produced by Tektronix were adopted to measure voltages and current signals in wire electrical explosion process under different initial charging voltages, and the measured data was entered into TDS.2024B digital storage oscilloscope for observation and record. As voltage of wire electrical explosion increases, the charging time of high-voltage power supply increases. However, the sum of the time for one wire electrical explosion (several microseconds) and single charging time of energy storage capacitor is less than the fastest wire feed rate of auto wire feeder, which meets the requirements of this design. Analyses of wire electrical explosion process from the aspects of voltage, current and deposition energy show that, increasing initial charging voltage can effectively accelerate wire electrical explosion process as well as the efficiency of continuous wire electrical explosion device. Nano Measure electron microscope particle size analysis programme is adopted for the statistical analysis of the size of Ni nano particle prepared; the Ni nano powder is steel grey. When the particle is small, it is approximately cube; when particle is big, it is sphere or approximately sphere; when initial charging voltage increases, i.e. the energy density applied on metal wire is improved, the distribution scope of the size of Ni nano particle can be effectively narrowed.