A High Voltage Isolated Pulse Generator using Magnetic Pulse Compression and Resonant Charging Techniques for Dielectric Barrier Discharge Applications

Background and Objectives: Dielectric Barrier discharge (DBD) is a suitable method to generating Non-thermal plasma at atmospheric pressure, which utilizes Pulsed power supplies as exciters. Increasing pulse voltage range and frequency and compactness are important issues that should be taking into consideration. Methods: The high voltage pulse generators which are introduced in the literature have some disadvantages and complexities such as need of additional winding to reset the transformer core and operating under hard switching which increases electromagnetic noise and loss. The leakage inductance of the high voltage transformer increases the rise time of the pulse which is undesirable for DBD applications. The energy stored in the leakage inductance causes the voltage spike across the switch, witch necessitates the use of snubber circuits. The main contribution of this paper is a new high voltage pulse generator with the following characteristics, ۱) a capacitor is paralleled with the main switch to reset the transformer core and to provide the soft switching condition for the switch. ۲) The resonant charging technique is used which doubles the secondary winding voltage which reduces the turns ratio of high voltage transformer for a certain output pulse peak. ۳) The sharpening circuit using magnetic switch produces a sharp high voltage pulse. Results: The proposed high voltage pulse generator is designed and simulated using Pspice software. To verify the theoretical results,  a prototype with the input voltage ۴۸ V, the output voltage pulse ۱.۵ kV, and the rise time of the output pulse ۵۰ ns is constructed and tested. Conclusion: This paper proposes a new pulse generator (PG). The proposed PG uses three techniques named forward, resonant charging, and magnetic switch to produce a high-voltage nanosecond pulse. The resonant charging double the secondary voltage of the pulse transformer, which causes reduction in turn ratio of the pulse transformer and decreases the weigh, volume, and price of the PT. The magnetic switch section finally produces a nanosecond high-voltage pulse. The magnitude of the output pulse can be varied using the input source voltage, the MS reset current and the duty cycle. The core of the pulse transformer resets by using a capacitor paralleled with the switch and the PG does not need any additional reset winding like the conventional DC-DC forward converter.