Development of a dynamic discharge model on wet contaminated insulators taking the discharge propagation into account

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K04329
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: The Open University of Japan (2021-2023); Nagasaki University (2019-2020)
• Principal Investigator: Yamashita Takahiko 放送大学, 長崎学習センター, 特任教授 (50182499)
• Co-Investigator(Kenkyū-buntansha): 古里 友宏 長崎大学, 工学研究科, 准教授 (70734002)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 汚損沿面放電 / 水溶液 / 抵抗率 / 接触面積 / 電流密度 / 二次電子放出係数 / 放電維持機構

Outline of Final Research Achievements

Propagation model of a surface discharge on water was developed. Voltage/current waveforms are calculated using a double-exponential function which assumes the resistance of water decreases with increasing discharge contact area. A conductive disk having a given potential is used to model the discharge contact area and the temporal variation of the radius of the disk is discussed. The electrostatic field calculation at the needle-to-water gap is performed to determine the initial discharge contact area. Expansion of the contact area in the creepage direction is evaluated by the electric field calculation at the edge of the conductive disk. The velocity of the expansion increases with the applied voltage. The maximum contact radius increases with decreasing conductivity of water under the same applied voltage. The tendency of simulation results is consistent with the previous observation results of the discharge propagation.

Free Research Field

高電圧工学

Academic Significance and Societal Importance of the Research Achievements

汚損沿面放電の進展特性や水上放電の電圧電流特性などをシミュレーションによって求めることができるので，これまで主に実験を通して行われてきたがいしの耐汚損設計・評価，ポリマーがいしの劣化評価，水処理装置の設計や運転制御などに利用可能である。また，分野毎に取り扱いが異なる汚損沿面放電と水上放電の研究成果を相互に活用できる。