Analysis of folded pulse forming line operation

Area of Science:

• Electrical Engineering
• Electromagnetics
• Pulsed Power Technology

Background:

• Compact pulse forming lines (CPFLs) are crucial for pulsed power applications.
• Existing CPFL designs face limitations in pulse fidelity and compactness.
• Novel approaches are needed to improve CPFL performance and reduce size.

Purpose of the Study:

• To explore a novel compact pulse forming line (CPFL) concept.
• To investigate the use of folded transmission lines and high-breakdown dielectrics.
• To understand the factors contributing to pulse shortening in CPFLs.

Main Methods:

• Fabrication of a small-scale folded CPFL using surface-mount ceramic multilayer capacitors.
• Development of a 10 kV class CPFL utilizing a polymer-ceramic nanocomposite dielectric.
• Electromagnetic modeling using the particle-in-cell code ICEPIC (2D and 3D).

Main Results:

• A small-scale CPFL delivered a 300 ns flat-top pulse.
• A 10 kV class CPFL produced a 110 ns FWHM pulse, shorter than designed.
• 3D electromagnetic analysis identified bends as the cause of pulse shortening and distortion.
• Bends create external power flow, explaining pulse shortening and amplitude anomalies.

Conclusions:

• The folded transmission line CPFL concept is viable.
• 3D electromagnetic analysis is essential for accurately modeling CPFL behavior.
• Geometric features, specifically bends, significantly impact pulse characteristics in CPFLs.