5Herbert G E. Electrical insulating oils[C]// American Society for Testing and Materials Committee. Philadelphia, USA: [s. n.], 1988.
6Crofts D W. The static electrification phenomena in power transformers [R]. New York, USA: IEEE, 1986.
7Radwan R M, El-Dewieny R M, Metwally I A. Investigation of static electrification phenomenon due to transformer oil flow in electric power apparatus[J]. IEEE Trans on Electrical Insulation, 1992,27(2) :278-285.
