Pulsed and self electrical breakdown in biodegradable oil

Summary form only given, as follows. The fundamental breakdown physics of biodegradable oil is investigated with a set up that employs a cable discharge into a coaxial system with axial discharge and load line to simulate a matched terminating impedance. No discontinuities are created in the system lines when entering the discharge chamber with the implementation of a unique feed-through design. The entire impedance of the system is matched at 50 ohms. A novel design for impedance matching transitions from the discharge cable to the coaxial system to the load line allow for a sub-nanosecond response. Final results are measured on pulsed and self breakdown voltages of up to 200 kV. Self breakdown is achieved by charging the discharge cable and load line to +/- 100 kV respectively. Pulsed breakdown is achieved by charging the discharge cable and load line to +100 kV. Shorting the discharge cable generates a reflected negatively polarized pulse causing breakdown. High speed electrical and optical diagnostics have temporal resolution down to several 100 ps A complete range of information from amplitudes of 0.1 mA to 1 kA with temporal resolutions of 300 ps is achieved by using transmission line type current sensors with fast amplifiers. Capacitive voltage dividers with fast attenuators are also used. Optical measurements are performed on low level light emission using spatially resolved, fast photo-multiplier tubes (risetime of 800 ps), supplemented with high speed photography and spectroscopic investigations on a nanosecond timescale Detailed optical and spectroscopic diagnostic along with high speed electrical diagnostics will address the mechanism initiating/assisting biodegradable oil volume breakdown.