Takahisa Imajo

Partial discharge pattern recognition for four kinds of electrode systems

The authors describe a method for recognizing partial discharge characteristics for four kinds of electrode systems. The method uses a neural network system with an input of phi -q-n distribution patterns. The theta -q-n distribution consists of the pulse count n versus the pulse height q and the phase angle phi . The learning characteristics and recognition characteristics of the neural network were investigated, and the recognition capability for a combined pattern signal input was shown. The effectiveness of the neural network system for partial discharge recognition is discussed.<<ETX>>

Thermal Brealdown and Thermal Runaway Phenomena in EHV Cables

The paper describes a new method of estimating thermal breakdown in EHV oil-impregnated paper-insulated cables with some experimental data. In the analysis it is shown with the computed results that the heat generation in the insulation can be exactly approximated by the average temperature of the insulation. In addition this method can calculate the critical voltage at which EHV cables go into thermal breakdown. The values here calculated compare agreeably with the breakdown voltages of 500 kV OF cables.