Signal Processing Of The Residual Flux Measurements In The Iron Core Of Power Transformer

Because of the harm to power system caused by the inrush current and the impact of the residual flux of the power transformer iron core to the inrush current,A novel approach for residual flux simulation,measurement and signal processing was proposed.In the process of experiment on residual flux measurement,in order to obtain accurate acquisition and processing of the signals to be measured,the main research work is as follows:At first,based on the basic structure,type and basic working principle of the power transformer,this article built the simulation model of three-phase transformer,analyzed the impact of the residual flux of the power transformer iron core to the inrush current by simulation.Then a toroidal transformer magnetic core was used as an example to analysis the working principle of residual flux measurement by means of loading DC transient excitation.Then,the relationship between the residual flux and the measurable parameter,i.e.,the change of the transient current in the core winding,is obtained by modeling and simulation of residual flux of the power transformer iron core.Based on this relationship,the overall solution of signal processing for residual flux measurement is determined.The peripheral circuits are designed and emulated such as signal conditioning circuit,power circuit,etc.Based on F28335 DSP,a minimum system used in detection,processing and display of the sensor signal in real time is completed,and the corresponding function software is designed and tested.Finally,After completing the manufacture,welding and test of each module circuit board,the design of this paper is debugged through the experiment.And the availability of the design is verified by comparing the error with the data acquired with the oscilloscope.