A Saturable Pulse Transformer Based on Nanocrystalline Magnetic Cores for an Adjustable Nanosecond High-Voltage Generator

• Published in: IEEE transactions on plasma science 2023-10, Vol.51 (10), p.1-9
• Main Authors: Degnon, Mawuena R., Gusev, Anton I., de Ferron, Antoine Silvestre, Pecastaing, Laurent, Baranov, Aleksandr, Mielot, Christophe, Boisne, Sebastien, Barnes, Michael J., Senaj, Viliam, Kramer, Thomas, Novac, Bucur M.
• Format: Article
• Language: English
• Subjects: Circuit design; Cores; Energy storage; Engineering Sciences; Generators; High voltages; Hysteresis loops; Internal energy; Magnetic cores; Magnetic fields; Magnetic hysteresis; Magnetic materials; Nanocrystalline magnetic core; Nanocrystals; Pulse transformers; pulsed power systems; saturable pulse transformer (SPT); Saturation magnetization; semiconductor opening switch (SOS); Switches; Transformer cores; Transformers; Voltage generators; Windings
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2023.3284657

This article is devoted to saturable pulse transformers (SPTs), combining the functions of a pulse transformer and a magnetic switch. Two nanocrystalline magnetic cores are investigated in the SPT of an inductive energy storage (IES) pulsed power system based on a semiconductor opening switch (SOS). The first magnetic core has a square hysteresis loop (Br/Bsat > 90%), while the second core has a flat hysteresis loop (Br/Bsat \sim 4%). A test bench with an initially stored energy of 10 J is developed. The circuit design is discussed, and the magnetic materials are compared. Based on the features of the hysteresis loops, two nanosecond high-voltage (HV) SOS generators are tested, with the output voltage adjusted by tuning the input voltage and controlling the bias magnetic field. The influence of the optimal core saturation on the operation of the SOS diode is studied. An adjustable output voltage impulse of more than 200 kV amplitude with a 16 ns rise time is demonstrated on a 1 \text{k}\Omega resistive load.