Study on Valve Screwing technology for automatic Oil Extraction of Operating Transformer

For operating oil-immersed transformer oil extraction problem, this paper takes the most widely used oil plug type oil ex-traction valve as the research object, and conducts a study on the mechanical screwing oil extraction technology required for unmanned oil extraction. It is found that the unscrewing of the oil extraction valve is mainly divided into three stages: locking, partial preload and slackening. The mechanical characteristics of the above three stages are analyzed in the paper, and it is found that the preload force and the resistance moment are mainly functions of the angular displacement. Through the engineering empirical formula, the active torque negative feedback control system is established to obtain a more ideal angular displacement-time curve, and the control curve of active torque with time is obtained based on simulation, which provides suggestions and guidance directions for the transformer unmanned oil extraction technology.