## Abstract

Water tree characteristics have been investigated for low-density polyethylene by applying power-frequency ac voltages with high-frequency components, which are simulated output voltages of a pulse-width-modulation inverter. If we compare the water-tree length among single-frequency voltages, the water tree grows faster if the frequency is higher. However, if we superpose a power-frequency voltage onto the high-frequency voltage, the tree growth is suppressed. The tree length becomes shorter if the superposed power-frequency voltage is higher. This surprising result is explainable by considering that the zero-crossing of the applied voltage plays an important role for the tree propagation. In case that the high-frequency voltage is superposed onto a dc voltage, the dc voltage seems not to have any influence to the tree growth. This result can be also explained by considering the number of voltage reversals at the tree tip.

Original language | English |
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Pages (from-to) | 300-303 |

Number of pages | 4 |

Journal | Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report |

Volume | 1 |

Publication status | Published - 1997 Dec 1 |

Event | Proceedings of the 1997 Annual Conference on Electrical Insulation and Dielectric Phenomena. Part 2 (of 2) - Minneapolis, MN, USA Duration: 1997 Oct 19 → 1997 Oct 22 |

## ASJC Scopus subject areas

- Electrical and Electronic Engineering
- Industrial and Manufacturing Engineering
- Building and Construction