The Research Of Winding Vibration Based On Harmonic In The New Converter Transformer

At the same time of rapid development in power, coordinated development of theresources and environment is a challenge we face. At present electric power industryin our country, has to provide reliable power for national economy development, andensure that the power transmission and transformation engineering and ecologicalenvironment are friendly, it is the realistic subject electric power industry mostconcerned of. Dc transmission is very important to the optimal allocation of resourcesand the optimization of energy supply, has been widely used in the power system inour country. With the rapid development of UHV dc transmission in our country,contradictions between the UHV dc transmission project construction andenvironmental protection are becoming more and more prominent, the mostprominent is the noise pollution of converter station. Noise of UHV converter stationmainly comes from the vibration of converter transformer. The low noise newconverter transformer designed of the harmonic shielding principle and inductivefiltering technology can effectively filter harmonic current, prevent harmonic currentinflow into net winding, inhibit transformer vibration. Paper work is one of theresearch content of the national natural science foundation of China (51077045)"Harmonic influence mechanism and new method of restraining on Convertertransformer vibration". The fundamental research in this thesis can be summarized asfollows:The structure characteristics of the new converter transformer and the principleof working are researched. Analysis of the harmonic characteristic of the newconverter transformer in normal condition, concluded harmonic of windings in fourkind of conditions: putting into no filter,5thand7thfilter,11thand13thfilter andputting into5th,7th,11th,13thfilter;Transformer model in ANSYS is reasonable simplified, is simulated in fourkinds of conditions to get electromagnetic characteristics of the new convertertransformer. Electromagnetism load is needed in the next winding vibrationsimulation. Analyze transformer iron core magnetic circuit, the winding leakagemagnetic field and electromagnetic force, and observe the simulation results,summarize the relationship of winding current, leakage magnetic field andelectromagnetic force, the mechanism of inhibition winding vibration of the new converter transformer;Add transformer winging stay and end insulation to the electromagneticsimulation model, the force on the winding node got in previous step is loaded intothe new model, vibration displacement waveform under four kinds of conditions areobtained. Using MATLAB Fourier decomposition function FFT(x), frequencyspectrum analysis of the displacement data was carried out. The finite elementcalculation results show the vibration characteristics in four different conditions, itreveals inductive filtering technology significantly suppressed the vibration ofwindings;On the basis of new technology research and development platforms of powertransmission and transformation in Hunan University, add the new convertertransformer into platforms, set up vibration test platform. Testing winding workingcurrent and the reference point vibration acceleration waveform, compared withtheoretical calculation and the simulation results, found that both have certainsimilarity. In conclusion that model is correct, the simulation method is feasible.This thesis makes a study of the low noise new converter transformer’s windingvibration characteristics in harmonic conditions, revealed the winding vibrationsuppression effect of the inductive filtering technique, which indicates that the lownoise new converter transformer has a good engineering application prospect.