Effects of ions and waveforms on water tree initiation and propagation

In this paper, we describe an investigation of the effects of ions and waveforms on water tree initiation and propagation utilizing a new water electrode method. The results indicate that ferric ions contribute to water tree initiation and propagation. Moreover, a water tree was initiated when the waveform of a pulse simulating an inverter waveform was applied for 2 weeks even at room temperature, in spite of no ac voltage application.