Influence of pressboard ionizable groups on static electrification in power transformers

As a part of a research program in the field of flow electrification in power transformers, some fundamental studies have been engaged on the chemistry of this phenomenon. Previous works have shown that chemical composition of pressboards is highly involved in the kinetics and magnitude of the charge accumulation process. Present studies consist in focusing on the influence of the hydroxyl or carboxyl groups with regard to charge accumulation, measured from capacitive currents on insulated electrodes facing pressboard ducts. Special manufactured and modified pressboards have thus revealed that the phenomenon is highly related to carboxylic and hydroxyl groups content and also probably to the hydrophilicity of the oil/board.