T Tom Huiskamp

Breakdown Voltage and Recovery Rate Estimation of a Supercritical Nitrogen Plasma Switch

Supercritical fluid (SCF), characterized by high pressure and high density, combines the advantages of gas and liquid: high ability of mass transfer and high heat transfer. SCF has a high potential as an electrical switching medium owing to its high breakdown strength and fast dielectric recovery capability after electrical breakdown. One other significant characteristic of SCF as insulating medium is its low impact to the environment, hence it is proposed as an ideal substitute for SF6-an extreme greenhouse gas in power system circuit breakers. In this paper, the thermodynamic characteristics of SCF are introduced by the review of references. An experimental analysis of electrical breakdown phenomena of a supercritical (SC) plasma switch with pressure up to 180 bar is presented, focusing on the breakdown voltage variation as a function of the fluid pressure, gap width of the electrodes, and fluid flow rate through the gap. A thermodynamic model for recovery rate analysis of a gas insulated switch is proposed and its feasibility is discussed. The model is used to predict the recovery rate of an SC switch.

Pulsed Corona Demonstrator for Semi-Industrial Scale Air Purification

Although pulsed corona technology for air purification is widely investigated by the lab experiments, large-scale application has yet to be proven. Industrial systems require large flow handling and thus, high corona power. An autonomous semi-industrial scale pilot wire-cylinder type corona reactor has been constructed for air purification demonstrations. The reactor is powered by a 10-kW spark gap-based pulsed power supply, capable of generating 60-kV 100-ns wide pulses with 1-kHz repetition rate. The pulses are optionally superimposed on a 0-30-kV dc bias to enable electrostatic precipitation. The system has been successfully applied during several field and lab experiments. Conversion data as a function of energy density are presented for NOx, NH3, H2S, toluene, limonene, and fine dust removal. The system proves feasibility of large-scale air purification by pulsed corona.

Temperature and pressure effects on positive streamers in air

In this paper we investigate temperature and pressure effects on the properties of a positive pulsed streamer plasma. We use a corona plasma setup in which we vary the temperature between 303 and 773 K at atmospheric pressure and the pressure between 37.9 and 100 kPa at room temperature to achieve the same neutral gas density and compare electrical and optical (ICCD imaging) measurements carried out in both experiments.From the measurements we found that the dissipated plasma energy and the average streamer propagation velocity are both higher for the temperature experiments at the same neutral gas densities as in the pressure experiments. This suggests the existence of a specific temperature effect. A possible explanation for this effect is a higher streamer conductivity at high temperatures, as was previously found in the literature.

Design of a Subnanosecond Rise Time, Variable Pulse Duration, Variable Amplitude, Repetitive, High-Voltage Pulse Source

In this paper, we present a design approach of a single-line nanosecond pulse source by using a thorough analytical investigation and by verification with CST MICROWAVE STUDIO. Through detailed analysis and simulation, we arrive at a design for a fast rise time variable pulse duration pulse source which is able to produce 1-10 ns pulses with tens of kilovolt amplitude and less than hundreds of picoseconds rise time. This variable pulse duration is achieved by using telescopic antennas and ferrites in the pulse-forming line of the pulse source. Finally, we present a first implementation of a 5-ns pulse source with an oil spark gap for fast switching.

Experimental Investigation on the Effect of a Microsecond Pulse and a Nanosecond Pulse on NO Removal Using a Pulsed DBD with Catalytic Materials

In this study, an experimental investigation of the removal of NO from an atmospheric air stream has been carried out with a non-thermal plasma dielectric barrier discharge reactor filled with different catalytic materials. TiO

Visualization of a Coaxial Dielectric Barrier Discharge Driven by a Sub-ns Rising High-Voltage Pulse and Its Reflections

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B-Dot and D-Dot Sensors for (Sub)Nanosecond High-Voltage and High-Current Pulse Measurements

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