The Research Of Transformer Tank Vibration Power Flow And Windings Fault Non-Electrical Monitoring Method

With the power grid capacity expansion,Large-scale power transformer power transmission capacity and voltage-level is also rising.The capability have a direct impact on the performance of the power system safe and stable operation,so the reliability is most crucial to the power transformers for long-term run.At the same time, large-scale power transformer is one of the most important and expensive electrical equipments in the power system,it is extraordinary significant to monitor the transformer failure.In this paper, a simpifiled dynamical model of the transformer for a on-line transformer monitoring system is presented after the analysis of electrodynamic force and vibration transmission of transformer.To find the best position of measuring points in the tank,the response characteristics of transformer tank through the theory of the plate vibration power flow is researched.The non-electrical method which use transformer tank vibration to judge is presented for on-line transformer windings fault monitoring system.The paper is carried out the more specifically work in three aspects:Firstly,it is to establish the simplified model of transformer vibration by the analysis of transformer windings and core electrodynamic force as well as transformer vibration transmission.Secondly according to the transformer tank as a shell structure,it is used the method of the structure liked plate and shell vibrating power flow to study the tank response characteristics. First of all,the analysis and comparison to a simulation and experiment of a aluminum alloy plate had been done to verify the the method of the structure of liked plate and shell finite element power flow.Secondly,the FE model of transformer tank which type No. is SZ9—20000/35is established by ANSYS and use the method of FE power flow for analysis of tank vibration power flow which transmit by core.At last according to the experiment of the same type of the SZ9—20000/35 tank ,it is comparing the experiment results and simulation's to verify the simulation results,so it is provided for theoretical and experimental foundation of on-line transformer monitoring system using non-electrical method.Thirdly,studying the impact of windings precompact force to the vibration by analysis of the transformer coil axial dynamic model.Acoording to simplified vibration model of transformer,it is establishing the windings fault judge model of using the signal of tank which reflects the windings precompact force and used the verified experiment to test the method feasibility.The full text is divided into five sections.The first part is about the background,domestic and foreign research status of the project and objectives and contents of this paper. The second part describes the transformers vibration source and transmission channels as well as the source of the transfer vibration characteristics of the electromagnetic force.The third part includes introduction of the theory of finite element method of power flow for the structure of liked plate and shell,simulation of the SZ9—20000/35 tank by ANSYS FE model and the verification experiment of the sz9-31500/35 transformer. The fourth part analyzes the axial vibration model of the transformer coil,establishs the simplified dynamic model of transformer and describes the non-electrical method and the verified experiment for monitoring on-line transformer winding fault.The last part summarizs the whole paper and gives some advices for the future rearch.