Real Time Power Control in a High Voltage Power Supply for Dielectric Barrier Discharge Reactors: Implementation Strategy and Load Thermal Analysis

Abstract

Atmospheric-pressure plasma treatments for industrial and biomedical applications are often performed using Dielectric Barrier Discharge reactors. Dedicated power supplies are needed to provide the high voltage frequency waveforms to operate these nonlinear and time-dependent loads. Moreover, there is a growing technical need for reliable and reproducible treatments, which require the discharge parameters to be actively controlled. In this work, we illustrate a low-cost power supply topology based on a push–pull converter. We perform experimental measurements on two different reactor topologies (surface and volumetric), showing that open loop operation of the power supply leads to a temperature and average power increase over time. The temperature increases by ΔTvol~120 °C and ΔTsup~70 °C, while the power increases by ΔPvol~78% and ΔPsup~60% for the volumetric (40 s) and superficial reactors (120 s), respectively. We discuss how these changes are often unwanted in practical applications. A simplified circuital model of the power supply–reactor system is used to infer the physical relation between the observed reactor thermal behavior and its electrical characteristics. We then show a control strategy for the power supply voltage to ensure constant average power operation of the device based on real-time power measurements on the high voltage side of the power supply and an empirical expression relating the delivered power to the power supply output voltage. These are performed with an Arduino Due microcontroller unit, also used to control the power supply. In a controlled operation the measured power stays within 5% of the reference value for both configurations, reducing the temperature increments to ΔTvol~80 °C and ΔTsup~44 °C, respectively. The obtained results show that the proposed novel control strategy is capable of following the transient temperature behavior, achieving a constant average power operation and subsequently limiting the reactor thermal stress.

Plasma Control: A Review of Developments and Applications of Plasma Medicine Control Mechanisms

“…A visual depiction of an open-loop and closed-loop control strategy can be seen in Figure 2. [20]. For both, plasma medicine and industrial plasma applications, there is a technical need for reliable and reproducible treatments, which require the discharge parameters to be actively controlled [20].…”

“…[20]. For both, plasma medicine and industrial plasma applications, there is a technical need for reliable and reproducible treatments, which require the discharge parameters to be actively controlled [20]. Therefore, Neretti et al evaluated the temperature and average deposited plasma power to a substrate at 6 ms intervals where the applied voltage could be adjusted by the input DC voltage.…”

Validation of an indirect nonthermal plasma sterilization process for disposable medical devices packed in blisters and cartons

“…The nonthermal plasma reactor has been powered by the high‐voltage generator described in reference. [ 27 ] A sinusoidal voltage waveform of a 7 kV peak and 16 kHz has been selected to supply the load. The power supply was driven using the duty cycle control strategy, alternatively supplying the discharge with ON/OFF cycles.…”

Generation of meter-scale nanosecond pulsed DBD and the intelligent evaluation based on multi-dimensional feature parameter extraction

“…Currently, for conventional DBD reactors with a size of cm, single-point and single-acquisition methods, such as electricity (discharge current) and spectroscopy (emission spectrum), are applied. However, for DBD on meter-scale, the larger discharge area leads to a more obvious spatial distribution of discharge, which is more susceptible to electrode structure, gas-flow disturbance and local overheating [17][18][19]. Traditional evaluation methods such as discharge power calculation, spectral emission intensity, generally are analyzed in a fixed position, which is difficult to reflect the spatio-temporal information of large-scale plasma discharge; although the shooting of discharge images can evaluate the discharge uniformity, the high-resolution information is difficult to be captured for large-scale discharge.…”