High-voltage Pulse Source Research Articles

Pulsed power corona discharges for air pollution control

Successful introduction of pulsed corona for industrial purposes very much depends on the reliability of high-voltage and pulsed power technology and on the efficiency of energy transfer. In addition, it is of the utmost importance that adequate electromagnetic compatibility (EMC) is achieved between the high-voltage pulse source and the surrounding equipment. Pulsed corona is generated in a pilot unit that produces narrow 50 MW pulses at 1000 pps (net average corona power 1.5 kW). The pilot unit can run continuously for use in industrial applications such as cleaning of gases (100 m/sup 3//h) containing NO or volatile organic compounds (VOCs) or fluids (e.g., waste water). Simultaneous removal of NO and ethylene to obtain clean CO/sub 2/ from the exhaust of a combustion engine was tested at an industrial site. Various chemical processes, such as removal of toluene or styrene from an airflow are tested in the laboratory. We developed a model to analyze the conversion of these pollutants. To examine the discharges in the reactor we use current, voltage, and E-field sensors as well as a fast charge-coupled device (CCD) camera. Detailed energy input measurements are compared with CCD movies to investigate the efficiency of different streamer phases. EMC techniques incorporated in the pilot unit are based on the successful concept of constructing a low transfer impedance between common mode currents induced by pulsed power and differential mode voltages in signal lines and external main lines.

A high-voltage pulse source for electron-beam generation using field emission

A relatively simple high-voltage pulse source has been developed by means of which positive and negative pulsed voltages can be synchronously generated. The pulsed voltage source is a six-stage Marx generator. Capacitors in each stage were charged in parallel by a DC input voltage and were connected in series to generate pulsed high voltages. The connection was made using rotary spark gaps. Positive and negative pulsed high voltages can be generated at the same time by connecting a ground at a certain stage of a capacitor bank. The synchronization of positive and negative pulsed voltages can be made by inserting a fixed spark gap to a grounding connection. This pulsed voltage source can be used to accelerate a pulsed electron beam in a sample gas in which a synchronized pulsed streamer corona discharge can be generated. This process can be used to promote gas-phase chemical reactions as well as to oscillate lasers. >