Research On On-line Monitoring Technology Of Power Transformer Based On MPEEMD Vibration Analysis

Power transformer is the most critical segment in power system,and its stability of running state has great influence on the whole power system.Many kinds of technologies,including computer technology and sensor technology,make impressive breakthroughs and innovation with the developing of science and technology,and enhancing of the safety awareness.The research methods of power transformer running state monitoring become more diversiform,and also the algorithm models are more mature.Since Hilbert-Huang transform algorithm has been proposed,its processing effect on nonlinear and non-stationary signal has been widely praised.The application of this method to the diagnosis of mechanical fault monitoring has become mature and perfect.In recent years,this method also used to the field of vibration analysis in power transformers.Good results have been achieved.However,HHT in EMD screening processing in the process of the complex vibration signals of power transformer,exposed the endpoint effect,modal aliasing problems,and serious interference in the final decomposition,which caused part of the signal distortion and affect the processing accuracy of algorithm.Based on the analysis of the vibration principle of the power transformer,aiming at the existing problems of the EMD screening process,the thesis approach to a MPEEMD algorithm combined with the permutation entropy principle,to observe the screening effect through the simulation signal and the looseness fault and normal working state,iron core transformer under the deformation failure of vibration to EMD,EEMD,MPEEMD processing experimental data.From the comparison of some aspects such as decomposition of the inherent modal correlation,and mean square error of reconstructing signal parameters,the results show that compared with the traditional EMD and EEMD,MPEEMD algorithm for simple signal and the complex vibration signals of power transformer screening is more accurate,and energy spectrum observation of the Hilbert is more obvious after sieving.Designed the main control wireless measurement system with STM32F405 chip,on-line monitoring platform with LabVIEW,which constitute power transformer on-line monitoring system,and through the experiment platform provided by Shandong Hongruida Electric Power Equipment Co.,LTD,the research verified accuracy and practicability of the on-line monitoring system with MPEEMD algorithm.