A Compact Solid-State Bipolar Pulse Adder for Dielectric Barrier Discharges

To excite atmospheric pressure dielectric barrier discharges (DBDs) and to regulate the low-temperature plasma intensity, a compact all-solid-state bipolar pulse adder with nanosecond edges is developed. It uses two MOSFETs with their source terminals shorted to form a special half-bridge circuit, and each stage includes two such half-bridge circuits and one capacitor. One bipolar signal applied to both gates of these two MOSFETs can turn them on alternately. Combined with a magnetic isolated driver with primary windings in series, one bipolar signal from the primary side can drive many charging and discharging switches, which considerably reduces the number of required components in the drive circuits. A prototype was constructed and the test results were demonstrated. The designed bipolar pulse adder can generate repetitive bipolar square wave pulses with voltage up to ±8 kV, a pulsewidth of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.3\sim 500~\mu $ </tex-math></inline-formula>s, and pulse edges of around 45 ns. The size of the power circuit in this bipolar pulse adder is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$14.5\times 5\times 7$ </tex-math></inline-formula> cm, which is very compact. All the voltage amplitude, pulsewidth, dead time, and repetition frequency of the bipolar pulses can be adjusted continuously. They all affect the plasma intensity of DBDs. Experiments show that increasing the voltage amplitude and repetition frequency can multiply the intensity of plasma. Adjusting pulsewidth and dead time can affect the number of remanent charges and be used as a precise adjustment of the intensity of particles. The power efficiency of 69.7% was realized.