Research Of Temperature Characteristics Of Transformer Winding Based On Micro-grooves Composite Phase Change Technology

Transformer is one of the most important and expensive equipment in power grid.Its reliable operation directly influences the security and stability of the power grid.In general, the lost of a reliable insulating capability will impact the service life of the transformer. The main reason for the lost of a reliable insulating capability is the heated winding and the rise of internal temperature of the transformer. With the development of science and production, and with the increasing capacity of a single transformer, the production requirements of transformers are becoming much higher.Thus, One of common concern in the transformer manufacturing and electric power operating departments is the rise of winding temperature with the local overheating problem. The temperature rise of a transformer winding not only limits the load capacity of a transformer, but also influences the operation safety, reliability, service life and manufacturing cost of a transformer. Therefore, research on the temperature rise of a transformer winding has the significant influence on extending the insulation life of transformer.This thesis applies the Micro-Grooves composite phase change(MGCP) cooling technology in transformer. According to the principle of heat transfer and fluid mechanics, a finite model of the 1000 k VA three-phase transformer which based on Micro-Grooves composite phase change cooling technology has been established.Further study of the temperature field of the MGCP transformer's winding has been conducted. The main research work is as follows:Analyzed the transformer cooling mode and the current research status of MGCP cooling technology at home and abroad, put forward the research significance and the main research content of this article on the basis of this puts. For the transformer heating and cooling process, this thesis studied the relevant theories of transformer temperature rise and the generation process of transformer loss, analyzed the allowable temperature rise of common transformer, and established the theoretical foundation for the research of MGCP transformer in the temperature field.This thesis put forward the structure of MGCP transformer set basic assumption to the study and analyze the internal heat transfer of the MGCP transformer.Considering the special hollow structure of the winding, this thesis has studied the internal heat transfer process of the MGCP transformer.This thesis has established the temperature field model of MGCP transformerbased on the micro groove composite phase change cooling mechanism, and also simulated the three-dimensional temperature field by using ANSYS. On the basis of the establishment of MGCP transformer temperature field model, this thesis analyzed the characteristics of three-dimensional temperature field distribution inside transformer under three conditions: rated conditions, local overheating and load fluctuations. In addition, this thesis compared the temperature distribution of MGCP type transformer to the ordinary dry type transformer, analyzed the temperature distribution when the transformer works long hours. The result shows that the transformer which uses MGCP cooling technique has better radiating ability, it can effectively reduce the actual operation temperature of the transformer, and prolong the service life of the transformer.