Noise analysis of UHV power transformer and research on active noise reduction system

With the rapid development of the power grid and the increase of power demand, the voltage level of the substation is improving rapidly. The noise caused by the transformer becomes a serious problem because it affects the health of the surrounding residents. In this paper, the noise of 1000kV transformer in Shanxi is measured and analyzed. The results show that the transformer noise has low frequency characteristics, and the frequency is mainly concentrated in 100Hz and its integer times. According to the transformer noise characteristics, an adaptive active noise reduction system is designed based on least mean square (LMS) adaptive filtering algorithm. The influence of filter step size factor and filter coefficient on the convergence and stability of LMS adaptive filtering algorithm is analyzed through simulation. The active noise reduction system is built and then the noise reduction experiment is carried out. Achieved about 6 dB noise reduction.